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The article discusses the refugee crisis in Europe, which has come to be symbolized by an Italian island of Lampedusa. The author of the article analyses two pieces by Jarosław Mikołajewski, a reportage Wielki przypływ [Great high tide] and a children’s story Wędrówka Nabu [Nabu’s Wandering], and seeks the answers to the following questions. What image of Lampedusa emerges from the reportage? What is the impact of the refugee crisis upon the lives of its residents? And finally, what is their attitude to the Other? Following Mikołajewski’s thinking, the author reflects on the challenges that the immigrants “at the gates of Europe” pose. In her opinion, Mikołajewski’s stance is open and emphatic. The aim of introducing the theme of migrants into children’s books is to teach them to be responsible for others.

Tenualosa macrura is an endangered fish in Riau Province, which is classified as a protected fish. Therefore, the first step is to study the reproductive cycle, aiming o prevent these species from extinction. The observation was carried out for 13 months from January 2019 to February 2020 (except February 2019) in Indonesia's Bengkalis waters. This study's purpose was determined to determine the spawning season, fecundity, and behavior of this species. The results showed that the relationship between length and weight positively correlates with the length-weight of male T. macrura (R² = 0.84) and female (R² = 0.67), while the length-weight of all males and females were reported to be (R² = 0.95). Meanwhile, the relationship between fecundity and length-weight has no relationship. Furthermore, the spawning season lasted all through the year, and it occurred at every low tide (dark moon) and high tide (full moon). Despite being discovered occasionally in a limited amount, the greatest amount of T. macrura was reported between July and September each year.

EnglishIn the Island of Maranhao, coastal barrier systems can be divided into two main morphotypes: (i) Headland Spit Barriers, which are characterized by a beach attached transversely to the previous topography showing a steep gradient where there is continuous loss of sand on the eroded coast; and (ii) Mailand Beach Barriers, which are characterized by a lagoon-barrier-spur system anchored longitudinally to the previous topography. This latter morphotype originates from a large sediment transport via the coastal drift, whose extension is usually interrupted by the hydraulic spike effect, together with high tide prisms in the river mouths. The present study uses percussion and vibrocore drills to recover the sedimentary record, which is described in terms of its sedimentation, texture, structure and sedimentation facies. The results obtained demonstrate the stratigraphic nature of the coastal barrier in the Ponta da Areia Beach as a retrogradation sequence characterized by the migration towards the continent of a sandy spur. The radiometric dating of lagoon sediments on the beach attested the age of 7,240 ± 30 years AP indicating that at this time, this lagoon-barrier-spur system extended out to sea. Recently, the construction of a coastal spire has changed this stratigraphic nature, and it has a progradational system in the immediate vicinity of the spike, where distal environments (backshore) are sotopostos by proximal environments (foreshore) portuguesNa Ilha do Maranhao os sistemas de barreiras costeiras podem ser divididos em dois morfotipos principais: (i) Barreiras de Praias Anexadas, que se caracterizam por uma praia anexada transversalmente a topografia antecedente exibindo um gradiente ingreme onde ha perda continua de areia na costa erodida; e (ii) Barreiras de Esporoes Arenosos ligadas a Cabecos de Promontorios, que se caracterizam por um sistema laguna-barreira-esporao ancorado longitudinalmente a topografia antecedente. Este ultimo morfotipo origina-se de um amplo transporte de sedimentos via deriva litorânea, cujo prolongamento e geralmente interrompido pelo efeito espigao hidraulico, junto a elevados prismas de mare nas desembocaduras fluviais. O presente estudo utiliza-se de sondagens do tipo percussao e vibrocore para recuperacao do registro sedimentar, o qual e descrito quanto a sua compactacao, textura, estruturas e facies sedimentares. Os resultados obtidos demonstram a natureza estratigrafica da barreira costeira na Praia da Ponta da Areia como uma sequencia retrogradacional caracterizada pela migracao em direcao ao continente de um esporao arenoso. A datacao radiometrica de sedimentos lagunares aflorantes na praia atestou a idade de 7.240±30 anos AP indicando que neste tempo, este sistema laguna-barreira-esporao estendia-se mar adentro. Recentemente a construcao de um espigao costeiro alterou esta natureza estratigrafica, passando a comportar um sistema progradacional nas imediacoes do espigao, onde ambientes distais (antepraia) sao sotopostos por ambientes proximais (foreshore)

For intertidal marine species, salinity and temperature are important environmental factors with conditions ranging from oceanic salinity and temperature at high tide to almost freshwater conditions due to rain accompanied by aerial temperature exposure at low tide. The interactive effects of these stressors across development to the juvenile is not known. We investigated the impacts of salinity (29–41 ppt) and temperature (20°–24 ℃) on holobenthic intertidal development to the five-armed juvenile asterinid seastar Parvulastra exigua. There was an interaction between the stressors with highest mortality in the high salinity and temperature (38 ppt, 41 ppt, 24 ℃) treatments. Developmental stage progression was enhanced by increased temperature. On day 1, there was an interaction between salinity and temperature on developmental stage progression, where high salinity (41 ppt) retarded development at the control temperature (20 ℃). The juveniles reared at 24 ℃ were smaller than those at cooler temperatures, suggesting application of the temperature size rule. The low (29 ppt) and high (38 ppt, 41 ppt) salinity treatments produced the smallest and largest juveniles, respectively. In the 35 ppt and 38 ppt salinity conditions at 20 ℃, most juveniles had the normal five-armed profile. Body plan development was perturbed with deviations from pentamery at 29 ppt, 32 ppt and 41 ppt and at 22 ℃ and 24 ℃ in formation of no armed juveniles and ones with abnormal arm number (4, 6, 7 arms). Normal development at 35–38 ppt and 20–22 ℃ reflects breeding period conditions. Prolonged exposure to low and high salinity and increased temperature is deleterious to development in P. exigua and alters body morphology with implications for function and survival.

Background Anthropogenic disturbance can negatively affect an animal’s energy budget by evoking movement responses. Existing research focuses mainly on immediate displacement as a disturbance effect, since this can be easily observed in the field. However, effects on movement over longer timescales are poorly examined and it is largely unknown if and to what extent they reflect immediate responses. Longer-term responses could for example be larger than immediate responses if birds, after disturbance, return to the original location and thereby travel twice the immediate disturbed distance. Methods We combined GPS tracking data with observational data to quantify the effects of anthropogenic (air force and walkers) and non-anthropogenic disturbances on distances travelled by roosting Eurasian Oystercatchers (Haematopus ostralegus) during the non-breeding season. We compared immediate displacement after a disturbance with distance travelled during the entire high tide period (longer-term response), while accounting for environmental factors. Additionally, we calculated energy expenditure due to disturbance based on observed disturbance frequencies. Results Disturbance resulted in an immediate displacement response of ~ 200 m (median). Air force disturbances tended to yield larger immediate responses than walker and, especially, than non-anthropogenic disturbances. Longer-term responses and immediate responses were approximately similar, suggesting that, over longer timescales, spatial disturbance effects in the study area remain confined to immediate effects. However, disturbances were infrequent (0.17 disturbances per bird per hour) and most disturbances were of natural origin (62%). Consequently, anthropogenic disturbance of roosting oystercatchers in the study area on average costs 0.08% of the daily energy expenditure. Conclusions Our results suggest that immediate spatial responses to disturbance can be a useful proxy for spatial responses over longer timescales. Over the non-exhaustive range of conditions investigated, energetic consequences of spatial disturbance responses for an oystercatcher in the study area are marginal due to low disturbance levels.

How animals partition activity throughout the day is influenced by processes that affect supply and obtainability of resources. However, as resource supply and usability are often entrained by the same diurnal pattern, it has been difficult to disentangle their relative importance. Given the strong influence that tide has on the distribution and accessibility of resources, intertidal systems present opportunities to examine questions surrounding the drivers of activity patterns. Here, we used multisensory biologgers to study the activity patterns of a coastal marine predator, sicklefin lemon sharks (Negaprion acutidens), in a tidally driven environment. Hidden Markov models were used to identify relatively high and low locomotory activity states, which were used as proxies for behavioural–activity states and to examine the factors underpinning variation in activity patterns. Although tide governs the spatial distributions of this species and showed some effect on sharks’ activity, diurnal light patterns were the predominant factor influencing behavioural-activity patterns, with the probability of high activity peaking overnight. Temperature and body size also had minor negative influences on the probability of animals being in the high-activity state. Interestingly, sharks were least likely to be in a high-activity state during high tide, a time of presumed high resource supply, contradicting the common assumption that this species forages during high tide. We suggest that despite the importance of the accessibility of resources, functional constraints, such as sensory (e.g., visual) and mechanical (e.g., swimming) performance ultimately underpin the activity patterns of intertidal marine predators through their influence on foraging success.

The spider genus Desis Walckenaer, 1837 is the type genus of the spider family Desidae Pocock, 1895. Desis spiders hide in silk sacs between rocks or shells during high tide and forage during low tide (Baehr et al. 2017). Four Desis species have been recorded from Asia: Desis gardineri Pocock, 1904 (India), Desis inermis Gravely, 1927 (India), Desis japonica Yaginuma, 1956 (Japan) and Desis martensi L. Koch, 1872 (Malaysia) (World Spider Catalog 2020). Until now, only one species of the family Desidae, Badumna tangae Zhu, Zhang & Yang, 2006, has been reported from China (Zhu et al. 2006). Here, we describe a new species of Desis and report the genus from China for the first time.

The purpose of this study was to determine the characteristics of nesting habitat of sea turtle in Lhoknga beach. The observation was conducted at three locations from January to March 2016. The study showed that the coastal slope average ranges 1.03 ° - 1.38 °. The average of nest temperature was 28.05 °C to 29.47 °C (inside the nest) and from 28.77 ° C to 29.95 ° C (at the surface of the nest). The width beach at high tide ranges from 20.17 m to 21.83 m and 31 m to 33.83 m at low tide. The nest humidity ranges from 20.5% -24.15%. There were six species of coastal vegetation recorded during the study, where station 1 has higher of density and diversity of the coastal vegetation. In general, Lhoknga Beach is suitable for nesting of the sea turtle. A total of 13 sea turtles (Lepidochelys olivacea) were nesting during the study, where station 1 had higher of nesting frequency.

Winslow Homer’s Eagle Head, Manchester, Massachusetts (High Tide) has been treated by art historians over the past fifty years as an unsettling and mysterious painting, one that does not meet expec...

The brooding gastropod Crepipatella dilatata can feed by scraping the substrate with the radula and by suspension-feeding, which also requires use of the radula. There is a “division of labour” for the radula among three discrete tasks associated with feeding: (1) removing mucous balls from the food pouch; (2) transferring the mucous cord from the neck channel to the mouth (both components of suspension-feeding); (3) scraping the substrate. We hypothesised that the proportion of time used for each feeding activity varies according to environmental conditions. Total radular activity in females was greatest at high tide and in summer. The rate of radular extrusion for ingesting the mucous cord varied seasonally and between brooding and non-brooding females. Non-brooding females exhibited higher rates of radular extrusion for ingesting the mucous cord and for scraping the substrate than did brooders. In females, radular activity in removing the mucous ball from the food pouch was strongly influenced by the tidal cycle during winter, reaching minimum values at low tide. Differences were recorded in substrate scraping among seasons and within tidal cycles, and among males, brooding females and non-brooding females. Brooding females displayed less rasping than non-brooders, since the area available for grazing was restricted by the egg mass. Throughout the year, including low salinity periods, males allocated a greater proportion of total radular activity to rasping than to removing the mucous ball or ingesting the mucous cord. The feeding behaviour of both males and females is modulated by salinity, but the principal determinants of radular activity are the mode of reproduction (brooding in females) and, in males, motility.

Gastropods are important protein sources for coastal communities. This study performed a case study in Nan'ao Island to compare the spatial and temporal variations of lipids, proteins, carotenoids and antioxidant capacity of commercially important gastropods. Seven commercially important gastropods were identified from the rocky shores of Nan'ao Island. All the gastropods analysed had medium to high fat, low protein, and a considerable amount of total carotenoids. From low tide zone to high tide zone, the total antioxidant capacity of gastropods increased dramatically. In terms of fatty acid composition, all analysed gastropods had PUFA/SFA >0.45, but only three species had n-3/n-6 >1.00. In conclusion, some gastropods, especially Lunella coronata coreensis and Monodonta labio, have good nutritional value and potential health effects. This study is the first comprehensive assessment of the nutritional properties of commercially important gastropods in different rocky shore microenvironments and different seasons.

Very little information is available on bottlenose dolphin (Tursiops truncatus) habitat use in the South-western Atlantic. It is, however, essential in understanding their ecology and to improve conservation management. In this study, habitat use of bottlenose dolphins was examined in Bahía San Antonio, an area frequented by the species. Given the large tidal amplitude and extended intertidal zone in this bay, special focus was given to the intertidal vs subtidal habitat use patterns. Bottlenose dolphins were observed in only half of the surveyed area, with on average 1 dolphin group encountered per 100 km surveyed. All dolphin groups were seen in shallow waters

Juvenile American horseshoe crabs, Limulus polyphemus, express both daily and tidal rhythms. To determine if, and how, tidal cues influence the expression of these rhythms, we exposed 25 animals to artificial tides, and 17 to artificial tides with inundation, both with a 12:12 LD cycle. In the first experiment, 24% expressed daily rhythms of activity, 24% tidal rhythms, 12% a combination of the two, and the rest were arrhythmic. Under subsequent atidal conditions some expressed daily rhythms, but more were circatidal. In the second experiment, 6% expressed daily rhythms, 71% tidal, 12% a combination, and 12% were arrhythmic. Those expressing tidal rhythms were more active during flood/high tide, while daily animals tended to be nocturnal. Under subsequent constant conditions, the majority exhibited circatidal activity, with some expressing one activity bout per day. We conclude that juvenile horseshoe crabs entrain to artificial tides, with inundation cycles providing stronger cues than water dept...

The objective of this study was to determine the implications of extreme tidal events on duration of stay and behavior of Semipalmated Sandpipers (Calidris pusilla) during migratory stopover in Cobequid Bay, Nova Scotia. This area is part of the Bay of Fundy and experiences the largest tidal range in the world. Radiotelemetry was used to monitor duration of stay of 30 adult and seven juvenile Semipalmated Sandpipers. Adults arriving in Cobequid Bay early in the migration period experienced a greater number of extreme high tides (> 15 m) that submerged preferred roost sites, and stayed on average 8.1 days longer than those that arrived later. Juvenile duration of stay was not significantly different from adults. When tides exceeded 15 m, Semipalmated Sandpipers engaged in over ocean flocking at high tide; however, this behavior was not observed when high tides were 13.6 m or less. These extra flights led to higher energy expenditure by early migrants, requiring an estimated 3.8 to 4.3-day increase in length of stay to reach the same mass as later migrants. In the future, predicted sea level rise could increase the frequency of extreme tidal amplitudes and result in greater energetic costs during Semipalmated Sandpiper stopover.

Biological Oxygen Demand (BOD) is generally used for determining water pollution levels in bodies of water. Estuary is a semi-enclosed body of water that can be polluted via land areas or rivers. This study was conducted to determine the spatial distribution of water pollution levels in the Suwung Estuary in Bali based on BOD 5 analyses conducted in January and February 2016. Samples were taken in 20 points (19 points in the Suwung Estuary and 1 outside the Suwung Estuary as control). BOD 5 samples were then analysed in the laboratory. Our BOD 5 analyses used the amperometric method based on the National Field Manual for the Collection of Data Water-Quality, Chapter A7. BOD 5 samples were taken at all tide cycles, during low to high tide and high to low tide. BOD 5 values ranged from 0.84 mg/L–9.47 mg/L during lowto high tide and 0.96 mg/L–8.75 mg/L during high to low tide. Results of the BOD 5 analyses showed slight contamination in the Suwung Estuary during both tidal conditions. The BOD 5 values’ spatial distribution showed higher values around cage aquacultures, rivers, the Suwung Landfill, and around the Benoa Harbour.

This study was conducted in tidal lowland at Banyu Urip Village, Tanjung Lago District, Banyuasin Region, South Sumatera. Samples were collected two times. The water sample was collected during high tide in primary, secondary, and tertiary canals. The result showed the seasonal variation of physical and chemical water parameters such as temperature 27 – 30 ºC, pH 3 – 5, DO 3.7 – 4.5 mg/l, phosphate 0.01 – 0.02 mg/l, TSS 108 – 232 mg/l, and EC 11 – 107 µmhos/cm. This study also identified 10 classes and 10 genera of phytoplankton. It has potential as a natural food source. The result revealed that physical and chemical water quality parameters were still suitable for aquaculture based on Government regulation of Republic Indonesia number 82 year 2001 about water criteria class III for fisheries. Meanwhile, the great challenge of tidal lowland for fishery management is low pH. Therefore, pre-treatment to increase pH before fish rearing is required.

A espécie Sotalia fluviatilis é pouco conhecida na região amazônica, principalmente no estado do Amapá, onde estudos são bastante escassos. O presente estudo tem por objetivo contribuir para o aumento do conhecimento sobre o padrão comportamental e percepção dos barqueiros sobre S. fluviatilis no porto do açaí. Este trabalho foi realizado em um ponto fixo localizado no Porto do Açaí. As observações foram feitas mensalmente no período de julho de 2013 a dezembro de 2013 em período matutino, junto às entrevistas com os barqueiros presentes no porto com a aplicação de um questionário de pesquisa com TCLE. Os padrões comportamentais mais frequentes observados pelo tucuxi foram deslocamento lento, deslocamento rápido e forrageio. Com relação a percepção dos barqueiros quando perguntados a maior parte dos barqueiros afirmou ver o boto tucuxi com frequência no porto, em grupos de dois a três indivíduos, realizando atividade de alimentação/forrageio. A presença maior da espécie no período de maré alta foi afirmada pelos entrevistados, corroborando com os dados de observação in loco. Segundo os entrevistados o tucuxi quando avistado localiza-se as margens do rio e que a presença da espécie é atribuída à alimentação descartada pelos vendedores de peixe do local e que hoje há menos animais em relação à 5 anos. Nesse sentido, espera-se o presente estudo contribua para informações sobre áreas de ocorrência de S. fluviatilis e futuramente subsidiar medidas de conservação para a espécie, tendo em vista a iminência da construção de um porto de escoamento de soja nas proximidades da área. Palavras-chave: Conhecimento popular, Etologia, região norte, cetáceos. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v5n4p119-124

Safety considerations for researchers shape ecological research approaches in dangerous aquatic environments. A series of recent studies has demonstrated that the moray Gymnothorax polyuranodon (Family Muraenidae) occupies freshwater in the adult phase. However, its potential use of tidal habitat remains largely unexplored, due partly to the challenges of performing underwater research within estuarine crocodile territories. In September 2017, opportunistic snorkel-based observations revealed individuals of this species occupying lairs at an upper tidal creek site during low tide (under freshwater conditions). This provided an opportunity to tailor field-based measurements of the salinity tolerance of this species a fortnight later during a more substantial high tide. Specifically, remote underwater video, snorkel and above-water observations of morays, combined with salinity measurements, reveal that G. polyuranodon is capable of tolerating salinity of at least 14.4 for several hours and can inhabit salinity of 19 for a period of several minutes. This finding, when viewed in synergy with other relevant studies of G. polyuranodon, indicates that the species is either catadromous or amphidromous or capable of either strategy.

This study aimed to investigate diet preferences of small fishes in a shallow coastal lagoon through analysis of their stomach contents.The 24 hours samplings was done during high tide at selected stations; mangrove areas and seagrass areas, both located at coastal lagoon of Setiu, Terengganu (N5o41.75’ E102o42’ to N5o 42.5’ E 102o41’). The small fishes were caught using seine nets (0.5 cm2), while the zooplanktons were collected using Kitahara zooplankton net (110 microns) then were preserved. All items found in the stomach were compared with the composition of the zooplanktons obtained from the water samples. During the sampling time, 10 species of small fishes were caught. There were higher number of fishes and zooplanktons caught from the seagrass areas than the mangrove areas. Nonetheless, diversity of zooplankton was higher in the mangroves. Overall, the number of harpacticoid was higher than all other food items found in the stomach of fishes caught from both areas despite the high number of calanoid copepods found in the lagoon

The crustacean Dimorphostylis asiatica inhabits the sublittoral zone and actively swims in the water at night. Males are positively phototaxic, and can be collected on the surface by using a light at night. The timing of this emergence was investigated in the field. Nearshore collections of males have demonstrated a clear rhythmic pattern, with emergence synchronized with both day-night and tidal cycles. The remarkable feature of this record was that the tidal aspect of the pattern was modified seasonally. While emergence was strongly synchronized with high tide during the winter and spring, tidal synchrony was scarcely detected in summer and autumn. Environmental factors that affect the seasonal modification of the activity pattern are still unknown.

The eggs of an estuarine terrestrial crab, Sesarma haematocheir (akate-gani), are incubated by the female for about one month. In estuarine crabs larval hatching is synchronized with the nocturnal high tide. To investigate whether the female or the embryo controls the actual timing of the hatching, one cluster of embryos was detached from each of two ovigerous females and reciprocally transplanted. Hatching of the transplanted embryos was divided into the following three patterns according to the number of nights until either (or both) of the females released their larvae. In Pattern I, the transplanted clusters both hatched on the same night that the donor females released their larvae. In Pattern II, the hatching of one of the transplanted clusters was not controlled by the host female, whereas hatching of the other transplanted cluster was obviously induced. Finally, in Pattern III, not only the induction of hatching, but also the time of hatching, was controlled by the female. Hatching profiles of transplanted embryos transferred to aerated conditions indicated that hatching requires three nights, and that each embryo also has an endogenous rhythm for hatching. The female seems to play two roles in hatching: i.e., initiation of the hatching process, and enhancement of hatching synchrony in each embryo. A plausible hypothesis explaining the mechanism of induction and the synchronization of hatching is presented.

In this paper we consider the possibility of using the absolute depression "bajo del Gualicho" (- 72 m), Rio Negro Province, Argentina, to generate electricity by means of a connection with the sea in the Gulf of San Matias, located about 25 km to the East (1). This would allow the formation of a large lake that would create an "artificial albufera" which will cover an area of about 1234 km 2 . This lake will be exposed to tidal by means of a combination of a channel and four tunels located between the sea and the lake. Taking the reference of Puerto San Antonio Este, the average tidal range reaches 6.73m (2), so that each high tide (lasting 6 hours. 20 minutes) would the water flow to the lake and the sea at low tide it would travel in the opposite direction. This project is made by means of a multidisciplinary research group with advice of Hydraulic Laboratory of University of La Plata and Renewable Energy Group of Academic Unit of Caleta Olivia (3), National University of Austral patagonia, Province of Santa Cruz. Also this project has the endorsement of Government of Rio Negro Province.

The endogenous activity rhythms of the South African endemic isopod Exosphaeroma truncatitelson were explored. Isopods were collected on days coinciding with either a neap or spring tide. High- and low-energy beaches, which vary in the intensity of wave action, were selected as study sites. Isopods, in groups of 10–30, were placed in glass tanks with different experimental conditions: darkness + no sand, darkness with sand and natural ambient light (no sand). Activity of the isopods was measured for 50 h by recording the number of isopods swimming actively during a 30-s period. These isopods exhibited an endogenous activity rhythm which coincided with the tidal cycle even though removed from their natural habitat. Cosine curves were fitted to the observed activity data and statistical differences across variables were investigated. Peak activity was shown to occur shortly after high tide. Similar activity cycles were observed for both neap and spring tides and for different times of the year. Results also...

1. The isopod, Excirolana chiltoni is found buried in the sand in a narrow zonal band on the high intertidal beach during low tide and emerges only during high tide to swim and forage in the wave wash. The position of the zonal band during low tides bears a consultant relationship to the level of the water line during the preceding high tide. Because of this relationship the isopod zone moves up and down the beach on a fortnightly schedule which corresponds to the semi-monthly variation in tide amplitudes (the spring-neap cycle). 2. Excirolana chiltoni stores considerable quantities of mineral prior to ecdysis in localized concretions of the integument (dermoliths). 3. Molting takes place in two steps. First the posterior portion of the isopod including the abdomen and last 3 thoracic segments is cast which is followed by the casting of the anterior portion of the animal. Isopods which are in the process of molting can be easily recognized since the newly exposed posterior exoskeleton is fully expanded before the anterior cast is made. 4. The development of dermoliths and the relative abundance of half-molted individuals were used to determine the frequence of molting in a field population which was sampled at 2 day intervals for a period of a month. These data indicate that molting is largely if not entirely restricted to the weeks preceding new or full moon when the amplitude of the tides is increasing. 5. Excirolana chiltoni also shows fortnightly periodicities in feeding and the degree to which it is infested with external parasites. 6. Indirect evidence suggests that the release of young also follows a fortnightly schedule and is most intense at the same phase of the spring-neap cycle that the population molts. Females retain their broods internally and might therefore be capable of controlling the timing of birth with considerable precision. 7. Synchronous molting was not as apparent in populations which were held under non-tidal conditions in the laboratory. 8. Synchronization of molting and birth to the ascending series of high tides and the storage of mineral reserves prior to ecdysis are interpreted as adaptations which serve to decrease the probability of an isopod being marooned above the waterline for extended periods of time where it would be subject to a high risk of death by desiccation.

The community structures of bacteria, the relationships between selected ecological factors and these communities in seawater were investigated in an underground in situ pipe eco-farming system including the underground pipes, the natural mangrove environment and the reservoir in mangroves of the Beilunhe Estuary, Guangxi, China. The seawater samples were collected on August, 1 (high tide), 8 (low tide), 15 (high tide), 2012 in turn. The profiles of Polymerase Chain Reaction-denaturing gradient gel electrophoresis (PCR–DGGE) revealed an insignificantly horizontal variation in the bacterial community indices among the aforementioned areas ( p > 0.05). However, the diversity indices were significantly higher at the first sampling than the two later ones ( p p 2− ) content was considered to be a potential key ecological factor influencing the transformation of bacterial communities. These results imply that the effects of this eco-farming system on the bacterial communities are negligible and this system can be performed normally.

For the majority of animals, the ability to orient in familiar locations is a fundamental part of life, and spatial memory allows individuals to remember key locations such as food patches, shelter, mating sites or areas regularly occupied by predators. This study determined if gobies collected from rocky platforms and sandy beaches differ in their ability to learn and memorise the locations of tide pools in a simulated rocky intertidal zone. Intertidal rock pool gobies show acute homing abilities and, therefore, should be expected to display superior learning and memory capabilities. In contrast, it is unlikely that natural selection would favour similar learning skills in sandy shore fishes because they simply shift back and forth with the tides. The learning abilities of gobies were tested using small replica rock platforms, containing four tide pools that retained varying depths of water at simulated low tide. Gobies were categorised as having learnt the task if they were able to consistently locate the tide pool that retained the most water at simulated low tide as the pool with the most favourable conditions. Rock pool species were able to locate the deepest pool to wait out low tide for ~95 % of the trials, while species from sandy shores were found in the deepest pool ~10 % of trials. Despite repeated stranding, sandy shore fish continued to follow the tide out. We propose that rock pool species memorised the location of rock pools during simulated high tide enabling them to relocate the best refuge for low tide.

Intertidal Zone is an area with high biological diversity including vertebrates. In order to survive in area with rapid change of environmental condition, animals need to be adapted accordingly. One type of adaptations that mostly employed is structural adaptation specifically ones that related to locomotor performances. Differences on how to navigate during high tides or when the water level subsided as well as types of locomotion between skippers and remainers suggested that there might also be structural differences in their skeleton. This research is aimed to study the skeletal structure of two species that use different strategy in their locomotion. Two species of fish from two main groups of intertidal fish (skippers and remainers) were caught and preserved in 96% Ethanol. The skeletal preparation was made using Inouye's Alizarin Red Alcyan Blue Method. Data were collected by comparing skeletal structure between two species particularly the axial (vertebrae) and appendicular (pelvic, pectoral, caudal fin) skeleton. Based on the observation, skippers and remainers skeletal features has been adapted to different function during locomotion. Modifications on pelvic, pectoral and caudal bones were found in skippers and remainers. In B. bilitonensis, there are fusion of bones, reduction of some structures and also smaller bone area to provide agility. In remainers, modification mostly found in pelvic and pectoral fin. Pelvic fins possess larger and more rigid basal lepidotrichia as it was used as an attachment apparatus while fish cling to the substrate during high tide. In B. fuscus, pectoral fins are used as main propellers during swimming instead of caudal fins, hence larger bones area to provide more muscle attachment are observed in this species

A total of 477 juvenile Hippocampus patagonicus recorded in 80 sampling events were detected rafting on the surface during high tide at San Antonio Bay, northern Patagonia, Argentina. If rafting juveniles drift long distances beyond their original populations, they have the potential to form new populations, which may explain the wide distribution of H. patagonicus.

We studied habitat use by Hector’s dolphins Cephalorhynchus hectori in order toquantify the influences of location, season, time and tide, and to determine how frequently dol-phins use inner Akaroa Harbour where unattended gillnetting is allowed for 7 mo of the year(1 April to 30 September). T-POD acoustic dataloggers were moored in outer, mid- and innerAkaroa Harbour to quantify variation in habitat utilisation by Hector’s dolphins over a year.Acoustic detections were analysed via an information-theoretic approach, with model choicesmade via quasi-Akaike’s Information Criterion. The best model included all 4 factors ‘site’, ‘sea-son’, ‘time’ (since sunrise) and ‘tide’ (time since high tide) and 5 interactions (site × season, site ×time, site × tide, season × time, season × tide). Of the interactions, site × season was most impor-tant, with seasonal differences being much greater in the inner harbour than elsewhere. Nextmost important was site × time after sunrise, suggesting diurnal movement of dolphins within theharbour. T-POD data showed a much higher level of use of the inner harbour in winter than wasexpected, in dicating that the current compromise allowing gillnetting in this area poses a genuinerisk of entanglement.KEY WORDS: Hector’s dolphin · Habitat use · Time · Tide · Season

Migratory shorebirds wintering or staging on ocean coasts collect at high tide on roosting sites that remain above the flood line. However, some species of Calidris sandpipers spend the high-tide interval in flight over the ocean. In the winters of 2006–2012, the characteristics of high-tide flight by Dunlins (Calidris alpina (L., 1758)) were studied at Boundary Bay, British Columbia, Canada. At wind speeds of 1–6 m/s, flocks of Dunlins remained airborne over the ocean for up to 4 h at altitudes of >30 m. If winds were >10 m/s, the Dunlins coursed low over the waves. Ambient temperature was a significant determinant in the occurrence and duration of high-tide flight. In October and November, the Dunlins spent just as much time in flight before as after high tide, but in January, flight duration was 43% shorter after high tide than before high tide. The mean January temperatures were significantly lower than in October and November. The Dunlins were hunted by Peregrine Falcons (Falco peregrinus Tunstall, 1771), which captured 81 prey in 494 attacks. The maximum kill rate of 0.28 captures per hour of observation was recorded in the second hour after high tide, which suggests that predation risk is greatest for Dunlins that return early from high-tide flight.

Two life stages of fish were sampled to examine the fish biodiversity and the ecological role of Segara Anakan lagoon (SAL). The fish were observed in during 2004 – 2014 while the larvae were sampled twice monthly during the full moon and dark periods in daylight hours only over 11 month periods (Novembre 2005 to Septembre 2006) at 10 sites located at SAL, Cilacap. Each trip two samples of the high tide and low ebb periods were taken from each station. The mature fish were sampled at Klaces and Karanganyar. The fish were also collected from fisherman. At least 90 genera of 48 family (65 mature fish and 64 larvae) were recorded at SAL. Gobbidae (range between 67.3 – 72.9 %) and Engraullidae (16.7 – 19.3 %) are the two most abundant larvae captured. Of the fish, at least 40 genera belongs to 16 families are of resident species that inhabit SAL for whole their life cycles. In other hand, 50 genera belongs to 31 families use SAL as temporary habitat (migratory). This finding suggests the important ecological role of SAL for fish.Keywords : segara anakan lagoon, biodiversity, ekological role

A study on the abundance and distribution of Freshwater Eels was conducted in Pangi River, Maitum Sarangani Province. Three stations, 50 meters away from each other, were set starting at the mouth of the river with coordinates 06.02278° N, 124.52069°. In every station are three substations at the right side near the bank, at the center and at the left side near the bank. The study was done from a period of 5 months starting from October 2014 to February 2015. Sampling was done every Full moon and New moon of the month during the low tide and high tide fluctuation. Salinity and temperature were also monitored during sampling. The freshwater eels were identified using morphological characteristics. A total of 4,262 individuals had been collected for five (5) months of sampling, Freshwater eels were found abundant during new moon with a total of 4,249 individuals and only 13 individuals were collected during full moon. Results showed that two species of Freshwater eels has been observed on the area out of 18 species of Freshwater Eels, the Anguilla marmorata and the Aguilla bicolor pacifica. The study further showed that the Anguilla marmorata is most abundant with abundance index of 96.62%, frequency index of 100% and dominance index of 196.62%, while Anguilla bicolor pacifica had the abundance index of 3.26%, frequency index of 42.86% and dominance index of 46.12%. There are two types of bottom substrates observed in the area Station 1 had sandy while Station 2 and 3 had rocky substrate. Anguilla marmorata is more often seen in the rocky bottom since they prefer to hide under the rocks and gravely bottom. Catch per unit effort (CPUE) was computed to range from 0.075gm/hour to 500 gm/hour. Temperature was monitored to be within the range of 23°C-25°C for the entire sampling period. Further study is recommended to monitor the freshwater eels that migrating upstream the river of Pangi, Maitum, Sarangani Province, beyond Station 3.

Nekton tidal migration patterns were examined in oligo-mesohaline intertidal salt marsh creeks using underwater video observations collected throughout multiple tidal cycles (i.e., fl ood-ebb) during summer 2005-2006. Underwater video observations indi- cated that species composition and abundances varied with tide stage. Three intertidal salt marsh species (Fundulus heteroclitus, Morone americana, Menidia menidia) were the most abundant species observed. In general, resident species were most abundant in early fl ood and late ebb tide stages, whereas transient species were most abundant around slack high tide. F. heteroclitus displayed a consistent symmetrical tidal migration pattern and primarily occurred in early fl ood and late ebb tide stages. M. americana occurred throughout fl ood and high tides, but were largely absent from intertidal creeks during ebb tide. M. menidia was observed during all tide stages, but displayed no distinct migration patterns. The results of this study highlight the advantages and disadvantages of using underwater video for exam- ining small-scale tidal migrations of nekton in intertidal salt marsh creeks.

Penelitian ini bertujuan untuk mengetahui keragaman makrozoobenthos berdasarkan kondisi pasang surut, dan parameter lingkungan fisika dan kimia di Kuala Gigieng, Aceh Besar. Penelitian dilakukan bulan Juni 2011. Penentuan area dan titik sampling menggunakan metode random sampling berdasarkan pengaruh aktivitas pasang surut. Sampel diambil menggunakan Eckmann grab, kemudian diidentifikasi di Laboratorium Biologi Laut Jurusan Ilmu Kelautan Koordinatorat Kelautan dan Perikanan. Dari hasil penelitian ditemukan 3 kelas yaitu Malacostraca, Gastropoda, dan Bivalvia yang terdiri dari 12 spesies makrozoobenthos. Indeks keragaman Shannon-Wienner (H’) pada saat pasang, mean sea level dan surut didaerah Kuala Gigieng berturut-turut adalah 1,26, 1,446, dan 1,892, sehingga dapat disimpulkan keragaman dikategorikan rendah.

Populations of the American horseshoe crab (Limulus polyphemus) differ in broad areas of their biology. We observed a non-harvested, marked Florida Gulf coast population during their spring spawning (March–May) in 11 years across a 17-year period (1992–2009). Long-term changes occurred in the number of spawning pairs: the population was stable from 1992 to 2000 but increased markedly after 2000. Short-term variation in numbers of spawning pairs, unpaired females, unpaired males, and operational sex ratios was explained by changes over the season and during each week of spring tides and by differences in actual (not predicted) maximum high tide height. Wind direction strongly affected tidal inundation and the number of spawning horseshoe crabs. Tagging individuals revealed that females returned to the nesting beach less often than males and most females were re-sighted only within 1 week of spring tides. No animals were seen across more than 6 years. Implications for management are discussed.

Intertidal crustaceans have a high degree of physiological plasticity, which allows them to withstand periods of water emersion. In this study we examine the physiological constraints that determine the distribution and abundance of the intertidal porcellanid crabs Petrolisthes laevigatus and Petrolisthes violaceus. This study evaluates the distribution and abundance of the two species at different tidal heights, in relation to haemocyanin concentration and LDH activity, resistance to air desiccation, thermal tolerance, and resistance to hypoxic water. The results showed that Petrolisthes laevigatus was more abundant at the high tide level than Petrolisthes violaceus, which was more abundant at the low tide level. Petrolisthes laevigatus showed greater tolerance to high temperatures and lower tolerance to desiccation when exposed to air than P. violaceus, which was also more tolerant to hypoxia during prolonged exposure. No differences were found in haemocyanin concentration and LDH activity. These findings support the idea of an evolutionary gradient towards terrestrial adaptations. Of the two species, Petrolisthes laevigatus showed the most advanced physiological features for semi-terrestrial specialization. Los crustáceos intermareales poseen un alto grado de plasticidad fisiológica, lo que les permite soportar periodos prolongados de emersión. En este estudio se examinaron algunas restricciones fisiológicas que determinan la distribución y abundancia de los porcelánidos intermareales Petrolisthes laevigatus y Petrolisthes violaceus. En este estudio se evaluó la distribución de estas dos especies a diferentes niveles del intermareal, relacionándolos con la concentración de hemocianina y actividad de la enzima LDH, resistencia a la desecación, tolerancia termal y la resistencia a agua hipóxica. Los resultados mostraron una mayor abundancia de P. laevigatus en la zona alta del intermareal y de P. violaceus en la zona baja. P. laevigatus mostró una mayor tolerancia a altas temperaturas y una menor tolerancia a la desecación durante la exposición aérea que P. violaceus, que además fue mas tolerante a prolongadas exposiciones a la de hipoxia. No se encontraron diferencias en la concentración de hemocianina y actividad de LDH entre las especies. Estos resultados apoyan la idea de un gradiente evolutivo hacia la los sistemas terrestres. P. laevigatus mostró más adecuaciones fisiológicas para la especialización semi-terrestre.

The grass puffer (Takifugu niphobles) exhibits unique spawning behavior. Large numbers of fish aggregate to coastal spawning beds several hours before high tide during the spring tide. In order to examine the environmental and physiological regulation of this semilunar-synchronized spawning rhythm, the aggregating and spawning behaviors of the grass puffer were observed in the field, and in an aquarium without tidal changes. The fish aggregated to a spawning bed in the rising tidal phases both in the morning and evening during the spring tide, and several days after the spring tide. Spawning occurred on several days when large numbers of fish (200-1000) aggregated to the spawning bed. The timing of aggregation and spawning was tightly connected to the tidal changes; aggregation occurred 2-3 h before high tide, and spawning occurred 2 h before high tide. In the aquarium, in which a slope was constructed with pebbles, small groups of mature fish aggregated on the slope only in the rising tidal phases during and after the spring tide, when the fish aggregated in the field. However, there was no spawning in the aquarium. The aggregating behavior observed in the aquarium without tidal changes suggests that the semilunar reproductive rhythm is endogenously maintained with surprising precision during the spawning period in grass puffer.

The ichthyofauna and passing efficiency of fishways were surveyed in Geumgang estuary from May to October in 2009. The fishes collected were classified into 24 species, 23 genera belonging to 8 families. These 24 species consist of 17 freshwater fish species, 3 migration fish species and 4 peripheral freshwater fish species. Seasonal function of fishways showed the migration from May to June and returning to the reservoir of fishes be washed out to sea when sluice gate open by rainfall in July and August. Most of the fishes catched in fishways moved from middle tide to high tide except for July. Fishes ascended fishways between the middle ebb tide and the ebb tide only July, because small freshwater swim against the fishway for leaching the reservoir through the newly formed flow when the water level at the fishway kept dropping. Small fishes that body length less than 200 mm mainly used gabion type fishways and fishes over 200 mm utilized a cascade type fishways. Based on the total individuals collected, the efficiency of the fishway was 1 % for the anadromous fish and over 80 % for freshwater fish. Therefore, it is concluded that ecological function of the fishway in the Geumgang estuary dike be very important not only for fish migration but also freshwater fishes`s returning.

and Summary The mating system of marine iguanas (Amblyrhynchus cristatus) was studied on Caamano islet with the aim of understanding how gregariousness of females and their behaviour influence the degree of polygyny attainable by males; the costs and benefits of territorial behaviour and feeding pattern of territorial males were estimated by their influence on body condition and mating success. The mating readiness of females was well synchronized to only 24 days in Jan. Females moved daily to the intertidal zone to forage and showed high fidelity to their resting sites. Males defended territories in the colony and not individual females. Two types of territory existed: resting-territories where females stayed during high tide and overnight, and transit-territories through which females passed on their way to and from foraging areas. Territoriality of males began at the end of Oct., immigrant males from Santa Cruz arrived about one month later and evicted a few of the resident males. Males stayed on their territories until the end of Jan. when the territory system broke down rapidly. During the reproductive period males shortened their foraging time and even fasted for some time in Jan. (median fast duration 12 days). They lost up to 26% body weight during this period and recovered from this weight loss only shortly before the next reproductive season. Long term records (max. six consecutive seasons) of a few males suggest that males slowly lose weight over several seasons. Weight loss of males within a season correlated significantly with their early-season weight, fasting period duration and number of copulations achieved. Courtship and copulation are described. Females normally copulated only once and only with territorial males. Breeding success of territorial males varied considerably, from 0 to 45 copulations within one season. Territory area, early-season weight of the owner and number of females on a territory correlated significantly with the number of copulations achieved. Territory quality is shown greatly to influence mating success of males. Other factors influencing breeding success and the cost of breeding are discussed and evidence against female mate choice is given. The convergence of the marine iguanas' mating system to that of pinnipeds in territorial spacing of males, variability of males' breeding success and selection for sexual size dimorphism is pointed out. Gregariousness of females has evolved under different selection pressures in the two groups and preadaptations for prolonged territory maintenance are shown to differ substantially in accordance with the different physiology of reptiles and mammals. Zusammenfassung Die Untersuchung des Fortpflanzungsverhaltens der Meerechsen sollte zeigen, (1) wie das Verhalten der Weibchen den Polygyniegrad der Mannchen beeinflust, (2) wie sich Territorial- und Fresverhalten der Mannchen auf ihren Fortpflanzungserfolg auswirken und (3) inwieweit gleiche okologische Bedingungen zu Konvergenzen im Sozialsystem der Meerechsen und Robben fuhrten. Alle Kopulationen fanden in einem Zeitraum von nur 24 Tagen im Januar statt. Weibchen kopulierten nur einmal und nur mit territorialen Mannchen. Die Weibchen wanderten taglich ins Watt zum Fressen und waren ihren Ruheplatzen in der Kolonie in hohem Mase treu. Die Mannchen verteidigten Territorien, jedoch nicht die Weibchen selbst. Zwei Territoriumstypen wurden unterschieden: Sitzterritorien, in denen sich die Weibchen bei Flut und uber Nacht aufhielten, und Durchzugsterritorien, durch die die Weibchen auf ihrem Weg ins Watt wanderten. Ende Okt. begannen die Mannchen sich territorial zu verhalten, etwa einen Monat spater kamen Mannchen aus Santa Cruz nach Caamano und vertrieben einige einheimische Mannchen von ihren Territorien. Gegen Ende Jan. brach das Territorialsystem rasch zusammen. Wahrend der Fortpflanzungssaison gingen die Mannchen nur kurz fressen bzw. fasteten im Jan. (Median der Fastenperiode: 12 Tage). Sie verloren dabei bis zu 26 % ihres Korpergewichtes und erreichten ihr Anfangsgewicht erst wieder kurz vor der nachsten Fortpflanzungssaison. Daten aus maximal 6 aufeinanderfolgenden Jahren lassen auf einen allmahlichen Gewichtsverlust der territorialen Mannchen uber mehrere Saisons schliesen. Der Gewichtsverlust innerhalb einer Saison korreliert signifikant mit dem Anfangsgewicht, der Fastendauer und der Anzahl der Kopulationen der Mannchen. Der Fortpflanzungserfolg der territorialen Mannchen variierte von 0–45 Kopulationen in einer Saison und korrelierte signifikant mit dem Anfangsgewicht der Mannchen, der Territoriumsflache und der Anzahl der Weibchen auf dem Territorium; er wurde insbesondere von der Territoriumsqualitat bestimmt. Weitere Faktoren, die den Fortpflanzungserfolg der Mannchen und die durch die Fortpflanzung entstehenden Kosten beeinflussen, werden diskutiert sowie Evidenzen gegen eine Partnerwahl durch die Weibchen. Das Fortpflanzungssystem der Meerechsen zeigt bezuglich Territorialstruktur, Variabilitat des Fortpflanzungserfolges der Mannchen und Selektion auf Sexualdimorphismus uberraschende Konvergenzen mit dem der Robben. Die Geselligkeit der Weibchen hat sich bei Meerechsen und Robben unter verschiedenen Selektionsdrucken entwickelt. Die Praadaptationen der Mannchen, die ihnen erlauben, sich lange auf einem Territorium zu halten, unterscheiden sich stark auf Grund der unterschiedlichen Physiologie von Reptilien und Saugetieren.

On Cousin Island, Seychelles, male ghost crabs mostly constructed their copulation burrows around new moon. The burrows were sited below the high tide mark and therefore only lasted until washed away by the incoming tide. Large males were able to defeat small males in contests for burrows and so, to reduce the risk of eviction, small males built their burrows later on the ebbing tide than large males, after the period when fights for burrows were most frequent. There was also evidence that small males built their burrows on stretches of beach presumed to be inferior, because the burrow density was lower.

We studied the impact of human disturbances on the feeding activities of Common Eiders Somateria mollissima wintering in Southwest Greenland. Eider activity and human disturbances (fast moving, open boats) were recorded during 9 days of observations in mid and late winter 2002. When most heavily disturbed, the feeding activity in the study area was reduced up to 60% on a daily basis. At the same time locomotion activity tripled. Logistic regression analyses showed that eiders attempted to compensate for lost feeding opportunities by rescheduling more feeding to periods where feeding conditions were relatively less profitable with respect to other variables. When undisturbed, eiders avoided feeding during high tide and intensified feeding at the start and at the end of the day, but these tendencies were levelled out if eiders were disturbed. When disturbed, the time interval and the distance to the last disturbance were both significant explanatory variables for the feeding activity. There was a cumulative effect of repeated disturbances on the feeding activity if disturbances were close in time and space (

Late Albian amber from Charente-Maritime (southwestern France) contains the first known marine diatoms preserved in a fossil resin. Approximately 70 inclusions were assignable to the genera Basilicostephanus, Coscinodiscus, Hemiaulus, Melosira, Paralia, Skeletonema, Stephanopyxis, Trochosira, ?Aulacoseira, and to the order Rhizosoleniales. Some of them are represented by several species. This diatom assemblage is mainly composed of colonial planktonic genera, which are typical for coastal shallow waters. The newly found amber inclusions extend the fossil record of four genera and one order from the Late Cretaceous and support certain molecular phylogenetic assumptions regarding the diversifi cation of marine diatoms in the Early Cretaceous. The unusual introduction of diatom shells from the beach or sea by wind, spray, or high tide onto the resin fl ows was possible because the amber forest grew close to the seashore.

Individuals of Cerithidea decollata periodically migrate along mangrove trees, resting on the trunks during high water, and foraging on the surrounding muddy platform during low water. Groups, ranging from tens to hundreds of snails, aggregate on the trunks well before the incoming tide (1–2 h) at a level that will not be reached by the high tide, that is, from a few centimetres (around neap tides) to over 1 m (around spring tides) above the ground. We addressed two questions: (1) how can snails determine when to stop climbing and (2) how do snails determine the length of the path necessary to stop at that level. We used plastic pipes, 2 m long and 20 cm in diameter, along which snails crawled just as on their own trees. Experiments in which the pipes were lowered, raised or tilted indicated that snails were able to perform both tasks. Overloading the snails with lead weights showed that the estimate of the required travelling distance was probably related to the energy used to cover that distance. However, it was not possible to define how snails were able to establish the distance they needed to travel to avoid the incoming tide, although we were able to exclude any role of for visual cues or chemical marks present on substratum.

Boat-based surveys were conducted from August 2002 to July 2003 to study the activity patterns, spatial pattern of area use, and group characteristics of Sotalia guianensis in Sepetiba Bay, southeast Brazil. Predetermined routes covered the entrance and interior of the bay, resulting in 210 dolphin sightings during 3,300 km total effort. Data on activity were collected using scan group sampling with instantaneous recording after 5 min of observation. Dolphins were sighted more frequently in the entrance of the bay, where water is deeper, and salinity and transparency are higher, than in the interior of the bay, where the environment is more influenced by freshwater inputs. Foraging and feeding were the most frequent activities, and occurred predominantly between 0600 and 1000. Foraging and feeding peaked during ebbing, low, and flooding tides, while socializing predominated at high tide. Mean group size was larger in the interior of the bay and when seabirds were present. Large aggregations containing >100 individuals of Sotalia guianensis seen year-round indicate that Sepetiba Bay is an important area for this species in coastal Brazil.

The occurrence and extent of nighttime feeding by Dark-bellied Brent Geese Branta bernicla bernicla on salt marshes adjacent to their tidal roost site were assessed on the north Norfolk coast using position-sensitive radio transmitters. Nine birds were monitored on 143 bird-nights, and feeding was recorded on 87. The frequency of feeding by night varied widely between individuals. The mean proportion of the night spent feeding for one bird was 19.7 ± 8%. Of this, 59% occurred within ± 1.5 h of high tide. Neither the proportion of the whole night spent feeding nor the intensity of feeding around high tide varied with the length of the night or with time after sunset at which high tide occurred. The extent of nocturnal feeding was also independent of the brightness and duration of moonlight. The birds fed for significantly longer on colder nights, and there was a significant positive relationship between the proportion of the night spent feeding and maximum temperature the preceding day. Analysis of daytime activity budgets on inland pastures showed that the proportion of time engaged in nonfeeding, energy-expensive activities was also positively related to maximum daytime temperature. Increases in the proportion of the night spent feeding after warmer days were achieved by increasing the period of time spent feeding on either side of the high tide, not by increasing feeding intensity at high tide. It is concluded that the geese compensate for increased energy expenditure during the day by increasing the extent to which they feed at night. Implications of increasing energy expenditure as a result of disturbance during the day are discussed.

Activity patterns of the critically endangered Mediterranean monk seal (Monachus monachus) were examined in the Desertas Islands Nature Reserve in the archipelago of Madeira. Activity of seals at sea was recorded from 25 lookout sites positioned along the reserve’s coastline and correlated to site location, season, time of day, and state of tide. From 1994 to 2005, monk seal activity, related mainly to the reproductive behaviour of the species, was recorded primarily at the three pupping sites within the reserve. Activity was influenced by site location, season, and state of tide but not by the time of day. Activity was highest during the autumn and winter months and was related to the pupping and post-parturition necessities of the species, and during high tide, when the incoming action of the sea led monk seals to move out of coastal caves, which are used for resting and breeding. Differences in activity among the three sites monitored were attributed to the level of protection offered by these locations against wind and wave action. The findings of this study, the most extensive study of its kind, have enabled the identification of priority research, and conservation actions for the species in the area.

Fiddler crab Uca pugilator larvae are released within estuaries near the time of high tide and are exported offshore to undergo development. Previous studies indicate that zoea-1 larvae use selective tidal-stream transport (STST) to migrate from adult habitats to shelf waters. In areas with semidiurnal tides, this behavior is mediated by a circatidal rhythm that is characterized by upward swimming toward the surface during ebb tide, followed by a descent toward the bottom during flood tide. We tested the hypothesis that U. pugilator zoeae from different tidal regimes possess activity rhythms that match local tidal patterns. Ovigerous crabs with late-stage embryos were collected from areas with semidiurnal, diurnal, and mixed tides and from an area within a microtidal coastal lagoon. Following hatching, swimming activity was monitored under constant conditions for 96 h. Zoeae from semidiurnal and diurnal regimes possessed activity rhythms with free-running periods that matched the tides at the collection sites (≈12.4 and 24.8 h, respectively). Crabs from beaches with mixed tides displayed asymmetrical oscillations in swimming activity with dominant periodicities that corre- sponded to the semidiurnal and diurnal constituents of the tides. Zoeae from microtidal areas pos- sessed rhythms that were similar to those observed in crabs from areas with semidiurnal tides. At all locations, peaks in activity occurred during the time of expected ebb currents, which is consistent with STST behavior favoring seaward transport. Differences in larval activity patterns suggest that STST behaviors are controlled by separate circatidal and circalunidian clocks or paired circalunidian clocks coupled in antiphase.

Results from students’ research on horseshoe crabs are not often readily available to other workers. A review of these studies has shown that during 6 years since the first published studies, the distribution of horseshoe crabs around Singapore’s main island has remained unchanged, the density of mangrove horseshoe crabs, Carcinoscorpius rotundicauda, at two sites has remained stable, and periods of high and low reproductive activity during the year have been confirmed. The student studies indicated that juvenile C. rotundicauda concentrated at the high tide zones of the mudflats along the Strait of Johor, and smaller juveniles were found on the mud surface and in the small streamlets. Adults were found spread more evenly over the mudflats from the high to low tide zones, on average about 3 m apart, and commonly buried or found in the larger streams among the mangroves. Feeding preference studies suggest mangrove horseshoe crabs are not particularly selective feeders. Sex ratios remained approximately 1:1 all year and at all sites, and mean percentage growth during ecdysis was 34 %, with little difference between the smallest crab of 1.1 cm and the largest of 90.1 cm. A mortality study found death rates of mangrove horseshoe crabs higher at a polluted site (19.8 %) than at a less polluted site (7.5 %). Island wide distribution studies showed that while there is a thriving population of mangrove horseshoe crabs around the north-west, by contrast, Tachypleus gigas, the coastal horseshoe crab, is still very rare around Singapore, but an encouraging finding was the first reported sighting of T. gigas juveniles at one site. These studies, although small and of short duration, are important for the regular monitoring of the current status of horseshoe crab populations around Singapore and offer a major contribution to the understanding of horseshoe crab ecology in the country.

Sea turtles have a high reproductive output and high mortality at early stages of the life cycle. In particular, many nests are laid below or close to high tide lines, and subsequently large numbers of eggs may be inundated and destroyed. A common conservation procedure is to relocate such doomed eggs to higher ground. This article examines this practice in the light of recent data revealing that some individual turtles tend to nest relatively near the water and others relatively higher up the beach. Discussion is focused on the question of why apparently poor placement of nests has not been selected against. Comparison between the ecology of leatherback and hawksbill turtle nesting beaches suggests that predictability of environmental conditions on the nesting beaches has an important influence on patterns of nest-site selection. Options are outlined for the management of nesting beaches where a high proportion of turtle eggs is subject to destruction by flooding.

Twelve species of brackish and freshwater ostracods were collected from the island of Yakushima in southern Japan. Six species, belonging to the genera Cypria, Dolerocypris, Stenocypris, Schellencandona and Paracypria, are new and are described herein. The genus Schellencandona is reported for the first time outside Europe. Although a wide range of apparently suitable habitats was sampled for ostracods across the island, all specimens were recovered from or near the coast; further inland yielded no ostracods. The freshwater habitats around the coast of the island consist of springs and rockpools at the top of the shore above most high tide levels.