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In this study, a female specimen of common sole (Solea solea) with 36.7 cm in total length and 466.0 g in total weight was caught off Ordu region (eastern Black Sea, Turkey) with trammel net at 10 m water depth on May 6, 2021. The age of specimen was determined to be 6 years old. Measured total length were the maximum value of Solea solea in the Turkish coast of Black Sea. [ABSTRACT FROM AUTHOR]

A five years old male individual of Spicara flexuosa was captured by trammel nets on February 13, 2021, at 15 m depths from Black Sea region. The total length and weight were measured as 235 mm and 144.06 g. This specimen is the largest that has been reported in coastal waters of the Turkey. Some morphometric aspects of the sampled picarel were also measured. The otolith weight was determined as 0.0563 g. Otolith length and width were measured as 8044.31 µm and 4596.48 µm, respectively. Further studies the abundance and distribution of S. flexuosa should be conducted in the Black Sea. [ABSTRACT FROM AUTHOR]

This study provides the length-weight relationships of 12 fish species that belong to ten families from the Köyceğiz Lagoon, Turkey; Dicentrarchus labrax (Linnaeus, 1758); Diplodus annularis (Linnaeus, 1758); Diplodus sargus (Linnaeus, 1758); Dussumieria elopsoides Bleeker, 1849; Engraulis encrasicolus (Linnaeus, 1758); Oreochromis niloticus (Linnaeus, 1758); Gobius niger Linnaeus, 1758; Mullus barbatus barbatus Linnaeus, 1758; Sparus aurata Linnaeus, 1758; Siganus rivulatus Forsskål & Niebuhr, 1775; Solea solea (Linnaeus, 1758); Trachinotus ovatus (Linnaeus, 1758). A total of 720 fish samples were collected with fish barrier, trammel net, beach seine and cast-net. The growth type of D. annularis (b=3.148), D. elopsoides (b=3.089), G. niger (b=3.154), S. solea (b=3.124) was determined as positive allometry and E. encrasicolus (b=2.814), D. labrax (b=2.764), T. ovatus (b=2.901) was determined as negative allometry whereas D. sargus (b=2.995), M. barbatus barbatus (b=3.003), O. niloticus (b=3.088), S. aurata (b=3.009) and S. rivulatus (b=3.079) showed isometry. The results of this investigation will contribute to further fishery studies in the Köyceğiz Lagoon. [ABSTRACT FROM AUTHOR]

New records of Pseudocaranx dentex (Bloch & Schneider, 1801) and Seriola fasciata (Bloch, 1793) are reported from the Mediterranean Sea. During the period 2013-2017, we have collected several records of both species from the south-east coast of Sicily (Ionian Sea). On the basis of our and published data, we can consider S. fasciata as a relatively common species in the area, commonly caught with purse seine around FADs in summer and autumn; while, P. dentex remains basically a rare species, occasionally caught with trammel nets or gillnets. This work represents the first well-documented records of both carangid species in the south-east coast of Sicily. [ABSTRACT FROM AUTHOR]

Summary: The age and growth of three goatfish species Mulloidichthys flavolineatus (Lacepède, 1801), Mulloidichthys vanicolensis (Valenciennes, 1831) and Parupeneus forsskali (Fourmanoir & Guézé, 1976) from Egyptian Red Sea, Hurghada region were studied based on otolith readings. The fishing operated mainly by gill and tramml nets with mesh sizes renging from 0.5 to 3 cm. The maximum longevity of the three species was found to be 6, 5 and 5 years for M. flavolineatus, M. vanicolensis and P. forsskali respectively. The age I was the dominant age group forming 50.18% for M. flavolineatus and 46.13% for P. forsskali. While age group II was most frequent in M. vanicolensis (50.67%). The asymptotic length (L∞) and the growth rate (K) were estimated with 38, 33.3 and 31.6 cm as well as with 0.27, 0.37 and 0.32 per year for M. flavolineatus, M. vanicolensis and P. forsskali, respectively. [ABSTRACT FROM AUTHOR]

Data on the vigour and at‐vessel mortality (AVM) of 6798 skates (comprising Raja clavata n = 6295; R. brachyura n = 208; R. undulata n = 185, R. montagui n = 98 and R. microocellata n = 12) captured by commercial fishing vessels in the inshore waters of the southern North Sea and English Channel were recorded. AVM in longline fisheries averaged 0·44% across five vessels (0–1·47%), although skates were usually unhooked manually and did not usually pass through a bait‐stripper. AVM in otter trawls averaged 0·76% (0–2·35%), from four vessels fishing with tow durations of <1·5 h (southern North Sea) or 1–4 h (English Channel). No AVM was noted for skates taken as a by‐catch in drift trammel nets (soak times <4 h). Anchored tangle nets resulted in an overall AVM of 2·0–2·7%, but increased from 1·47% (13–28 h soak time) to 6·16% (42–53 h soak time). There were significant differences in the vigour of skates between gears, with R. clavata caught by longline and tangle nets in better condition than those captured by otter trawl or drift trammel net. Similarly, R. undulata caught by tangle net were in better condition than those caught by otter trawl. The vigour of R. undulata was also found to be higher than other skate species for both trawl and tangle net. In total, 5283 skates were tagged with Petersen discs and released, with recapture rates for the various combinations of vessel and gear ranging up to 24·8% for R. clavata. Whilst confirming a degree of post‐release survival, quantitative estimates of post‐release mortality for skates remain unknown. [ABSTRACT FROM AUTHOR]

Owing to commercial fishing during the late 1970s/early 1980s, targeted notothenioid species had become depleted around the South Shetland Islands. Herein we report subsequent changes in the prevalence of three species, Notothenia rossii, Gobionotothen gibberifrons and Notothenia coriiceps in Potter Cove, King George Islands/Isla 25 de Mayo, in a 33-year effort to monitor recovery. N. rossii and G. gibberifrons had been severely impacted by industrial fishing but in offshore waters N. coriiceps had never been commercially fished; however, all three species exhibit similar nearshore habitats and life history. We examined composition in trammel net catches during 2012-2016, augmenting a time series started in 1983. Our inshore results were consistent with those from offshore bottom trawl sampling in 2007 and 2012 around the South Shetland Islands: (1) continued increase in the abundance of N. rossii; (2) further decline in G. gibberifrons recruitment evidenced by low proportions of juvenile fish; and (3) a high abundance of N. coriiceps. Reasons for lack of recovery in G. gibberifrons remain obscure but seemingly relate to the dramatically changing ecosystem of the region due in part to climate as well as recovery among previously depleted upper trophic level species. Our results are also consistent with trends reported in seabirds that feed on juveniles of these notothenioids: decrease in the areas commercially fished. Under the regulation of CCAMLR, commercial fishing for finfish in the South Shetland Islands region (FAO Subarea 48.1) remains prohibited since 1991; results indicate that it cannot be reinstated. [ABSTRACT FROM AUTHOR]

The present research was carried out during Autumn 2016 with the aim of studying the technical and design characteristics of the widely used trammel nets in Lake Manzalah, as an attempt to be one of a data base that describe the different fishing gears used in Egypt. A number of net units were randomly used as samples. Results showed that such nets are used in collaboration with small fishing wooden boats (canoes) reinforced with a layer of fiber glass of the third class with an average number of 2 men. The dimensions of trammel net unit ranged between 20 and 25 meter long and a height of 0.5 to 1 meter. Trammel nets are formed of three netting panels, the stretched mesh size of the middle layer averaged # 40.82 mm while that of the outer layer was 125.24 mm. The upper and lower ropes were locally made of 3- strand staple fibers. Small sized cork floats were mounted on the upper rope (av. # 3 / 1 m) and lead sinkers to the lower rope (av. # 5 – 6 piece / m) of a total weight of 2-3 Kg per net unit. The netting materials were of polyamide monofilament of an average diameter (ɸ) 0.126 mm for the inner layer and ɸ 0.22 mm for the outer one. The horizontal hanging coefficients ranged between 0.60 and 0.70 for the outer layers and between 0.40 and 0.55 for the inner one. The results showed that such nets don't match the criteria for catching moderately sized fish (Average length 15 cm) of tilapia especially the mesh opening of the inner layer for conserving the fishery stocks and sustainable fishery. [ABSTRACT FROM AUTHOR]

Background: This report represents the first record of the sharpnose sevengill shark Heptranchias perlo in Guatemala's Caribbean Sea. Methods: Two H. perlo specimens were captured by artisanal fishermen of the coastal community, El Quetzalito. All specimens were captured with a trammel net, in waters of 200 m depth. Results: Both specimens were female with total lengths of 280 and 370 mm. Details regarding the identification and measurement of both specimens are presented. Conclusion: These specimens represent the first record of both species in Guatemalan waters. Also, this report further increases the species' range of distribution in the Caribbean and Central America. [ABSTRACT FROM AUTHOR]

Meagre ( Argyrosomus regius) is an emerging species in aquaculture considered a locally absent species in the Western Mediterranean. Little is known about meagre escape incidents from farms. To evaluate escape impacts and develop mitigation measures, knowledge about the behaviour of escaped meagre is necessary. In this study, a rapid dispersion of escaped meagre was observed following a simulated escape incident in a coastal Mediterranean farm, using acoustic telemetry (acoustic tag: AT) and mark-and-recapture techniques (external tag: ET). A small proportion of AT meagre (22.7%) remained within the farm boundaries 24 h after the simulated escape. A total of 84 meagre (9.2%) were captured by local trammel netters nearby the farm facility within the first 48 h after escape. Only two AT individuals (15.3%) were detected by acoustic receivers located in coastal areas within 2 days after dispersal from the farm and eight ET meagre (0.8%) were recaptured along the shoreline during the first week. Two AT individuals (15.3%) were considered to be dead by predation few hours after escape. The rest of the AT individuals ( N = 6, 46.2%) left the facility alive, and they were never detected by receivers nor reported back by fishermen. Thus, our results highlight the necessity of establishing escape mitigation strategies at Mediterranean fish farms, i.e. recapture programmes 24-48 h after the escape incident in collaboration with local fishermen, to diminish potential impacts related to meagre escapees. [ABSTRACT FROM AUTHOR]

Changes in fish assemblage structure caused by human activities, such as fishing, can alter trophic relations in fish assemblages. In this context, Marine Protected Areas (MPA) are efficient tools for habitat recovery and ideal environments for evaluating changes on the trophic structure resulting from human activities. The present work targeted fish assemblages from two no-take MPAs from the northern half of South Alentejo and Costa Vicentina Marine Park, established in 2011. Previous works reported positive effects on local fish assemblages after no-take MPA designation, and it is therefore important to further study its impact on local fish assemblages, especially concerning trophic interactions. Local fish assemblages were sampled (summer 2011, winter 2012, summer 2013 and winter 2013) using trammel nets. Diets were characterized and digestive tract contents of the 10 most abundant fish species were compared between the no take MPAs (treatment) and adjacent areas (controls), and changes evaluated as a function of time since protection. Results revealed significant differences between the diets of fish from protected and non protected areas, with crabs being the preferential prey in both protected and control areas but being more ingested outside the no-take areas. However, these differences were evident since the beginning of the study. Fish assemblages from the northern area presented significantly larger niche breadth and significantly increasing with time. This way, the main effects of no-take MPA implementation were directly visible on the niche breadth but did not directly impact the diet composition of the sampled fish assemblages, contributing however to reinforce the already naturally existent differences. This work provides important information regarding the effect of changes in the fish assemblage caused by MPA designation on the trophic ecology of fish. [ABSTRACT FROM AUTHOR]

We explore the capability, willingness and practicalities of data collection by skippers, and the feasibility of using these data to document fishing patterns and catch composition in the English inshore sector. Thirty skippers of under 10 m vessels in south coast England collected detailed information on the gear they used, species, size, proportion of catch retained and discarded as well as the reasons for discarding during daily fishing trips. Fisheries observers accompanied participating vessels on prearranged trips to independently record the catch levels and collect length data. The data from skippers showed significant differences between gear types on the level of daily catch with the daily catch for gill net, otter trawl and tangle net significantly higher than that of drift net, hand line and ring net. Discard rates varied between the different gear types with trammel net (27%) and tangle net (22%) showing the highest discards ratios, while hand lines (4%) the lowest. Comparison of the number of species recorded by skipper and observer on the same fishing trips shows that the number recorded by observer was two times that of the skipper indicating that skippers are poor at identifying species in the discarded catch as they do not pay a lot of attention to this portion of the catch. Catch data from corresponding trips also show low correlations between the self-collected data from skippers and data from observers. Accurate discard rates are important as they are applied to landings data to estimate total catch and therefore total fishing mortality. Results show that the skippers consistently underestimated the discard rates when compared to the observer data implying that weighting factors will be needed if the data from skippers are to be used in stock assessments. [ABSTRACT FROM AUTHOR]

Fifteen fish species belonging to 14 genera from 12 families and seven orders were collected seasonally during 2014 to 2016 from 12 fishery surveys on bottom towel net, 2010 to 2013 monthly by stake net and trammel net in Amoy Bay, East China Sea, at depths of 5–40 m, for analysis of their length–weight relationships (WLRs). [ABSTRACT FROM AUTHOR]

Effective species management requires good knowledge on vessel dynamics, either at a stock basis or through the establishment of multiannual management plans as advisable under the new European Common Fisheries Policy (CFP). Achieving such knowledge on Portuguese multi-gear fisheries is challenging given the large number of species caught and the different management measures applied to potential target species. The latter ranges from no input or output controls to output controls based on individual vessel quotas (IVQ). To provide accurate regional knowledge to the CFP, the dynamics of vessels involved in the trammel net fishery targeting anglerfish ( Lophius spp.) was characterised based on onboard sampling data and logbook reports. The selected vessels were very dynamic, and were found to target other species such as hake ( Merluccius merluccius ), John Dory ( Zeus faber ) and octopus ( Octopus vulgaris ). Anglerfish landing trends can be explained by changes in abundance, quota availability and shifts/changes in fishing effort. Overall, the dynamics of these vessels varied with area of exploitation, IVQ value and anglerfish total allowable catch (TAC). These results show the influence of different management systems in the dynamics of vessels and the advantage of an IVQ management system, where fishers can spatially and temporally allocate effort. Results also highlight a fishing effort shift towards unregulated species in face of IVQ or TAC restrictions. [ABSTRACT FROM AUTHOR]

Cabrera National Park is a Marine Protected Area (MPA) located in the South of Mallorca, Balearic Islands, Spain. It has a valuable ground fishery that includes several species of crustaceans of commercial interest, such as the European spiny lobster Palinurus elephas . Lobster traps, although permitted and even promoted by the park's authorities, have been abandoned due to the higher efficiency and catch per unit effort of the trammel nets. This study evaluates traditional and modern lobster trap designs to determine the most suitable one as an alternative to trammel nets. The gear was first tested in an aquarium and consisted of a reed trap, a plastic trap and a metal trap, all three historically used in Mallorca, and a modern Japanese collapsible trap. By conducting behavioral observations and exposing 40 lobsters to the traps it was found that the collapsible trap captured 20% of the lobster exposed to the trap, while the plastic trap only 10% and the reed and metal trap only 2.5% and 0%, respectively. In addition, experimental trials were conducted in a fishing ground of Cabrera National Park using two 450 m long strings of traps. Each string was composed of 30 collapsible traps or 30 plastic traps, with traps spaced at 15 m intervals along the line. Lobster catches were 24 (0.8 lobster/450 m) in the plastic traps, but only 9 (0.3 lobster/450 m) in the collapsible ones. When considering that the minimum legal size for lobsters is larger than 9 cm carapace length (CL), only 9 lobster (0.3 lobster/450 m) could be landed after deploying 1800 traps, and all of them coming from plastic ones. To compare the effectiveness of traps with lobster trammel nets, 14 fishing operations were carried out with a total of 5950 m of net deployed. Thirty-three lobsters were captured (2.37 lobster/450 m) in the nets, of which only 17 reached commercial size (1.22 lobster/450 m). Although the collapsible trap has caught more lobsters in the aquarium compared to the plastic trap, the plastic trap performed better in the field. This appears to be due to the effects of bycatch species, particularly octopus. Our results stressed the necessity of implementing an evaluation of the lobster population dynamics to design more efficient management measures. The fishers themselves recognize the need to an agreement for changing the paradigm from maximizing catches to maximizing profit. [ABSTRACT FROM AUTHOR]

In this study the effects on the discard reduction of guarding net rigged prawn trammel nets were examined with the focus on catch composition and income of fishermen for the Mersin Bay small-scale prawn fishery. A total of 15 fishing trips were carried out between September and December 2011, using the commercial net and the alternative experimental net for comparison. The results revealed that catches of the main target species, green tiger prawn ( Penaeus semisulcatus), in the alternative nets were only 1.5% smaller than those of the commercial nets, and with a statistically insignificant difference (P > 0.05). However, the catch of the main discarded species, the invasive swimming crab ( Charybdes longicollis), mantis shrimp ( Rissoides desmaresti), and the blue crab ( Portunus pelagicus) were captured 85%, 66%, 75% less often in the alternative nets, with statistically significant differences (P < 0.05). Also reduced was the labour needed to remove the catch from the alternative gear as well as a reduction in the number of tears in the net. An 8% loss of revenue from landings was estimated when using the alternative gear, however, this difference was statistically not significant (P < 0.05). [ABSTRACT FROM AUTHOR]

We evaluated (1) the suitability of two alternative methods for fish monitoring: trammel net sampling and BRUV (Baited Remote Underwater Video), and (2) the potential to cross-calibrate the methods based on a set of shared species with high catch probabilities. A statistical power analysis concluded that BRUV can be conducted with sufficient sample size to perceive small changes in fish populations with high power, and therefore can be used as a sentinel monitoring method. We found that fish species detected by both methods amounted to almost a third of the number of species in each method's catch, and that 90% of these species are candidates for cross-calibration. 74% of the species at BRUV and 50% at trammel had occurrence probabilities above 10%, a reasonable threshold allowing stock assessment of these species. The sampled and predicted total species richness, extrapolated from the species accumulation curves, were almost identical across methods. We conclude that cross-calibrating the two methods and eventual replacement of the trammel method with non-destructive BRUV is feasible. The most effective areas of improvement are increased BRUV night-sampling effort and increased total sampling size to increase the statistical power of BRUV as a monitoring tool. This work has been supported under the Croatian Science Foundation under the project COREBIO (3107). [ABSTRACT FROM AUTHOR]

The ecological and socio-economic problems caused by abandoned, lost and discarded fishing gear (ALDFG) are increasingly of concern. Used primarily by coastal, artisanal, small-scale fisheries worldwide, marine gillnets and trammel nets, which have relatively high ghost fishing potential, account for about one-fifth of global marine fisheries landings. FAO and the Global Programme of Action for the Protection of the Marine Environment from Land-based Activities, hosted by the United Nations Environment Programme, as Secretariat for the Global Partnership on Marine Litter, commissioned this study to identify best practices to estimate ghost fishing mortality rates and levels, priority research needs, and the status of international monitoring and management of ALDFG and ghost fishing by marine gillnet and trammel net fisheries. Accurate estimates of total ghost fishing mortality levels can be made given quality data on the density of ALDFG retaining fishing efficiency, duration of ghost fishing efficiency, and total ghost fishing mortality level of a unit of effort of ALDFG over the full period that the derelict gear retains fishing efficiency. Recommendations to improve estimates of regional and global rates and levels of ghost fishing from ALDFG from marine gillnet and trammel net fisheries were made. An assessment was made and opportunities were identified to improve intergovernmental organizations' data collection protocols and management measures to prevent and remediate ALDFG and ghost fishing by marine gillnets and trammel nets. [ABSTRACT FROM AUTHOR]

Summary: The presence of gilthead sea bream (Sparus aurata) in the Black Sea, albeit sparse, has been known for many years. In recent years, it has been encountered in fishing nets, most commonly as by‐catch. In this study conducted in the southern Black Sea (Ordu) region, three female individuals were caught in trammel nets on October 9, 2017, and the largest individual was found to have a total length of 61.4 cm, a weight of 3080.6 g, and a gonad weight of 115.59 g. The metric and meristic characteristics of the largest individual sampled were also determined. [ABSTRACT FROM AUTHOR]

We studied the influence of trammel nets on the behaviour and spatial distribution of bottlenose dolphin in the Aeolian Archipelago, Southern Italy. Ninety-six dolphin groups were followed for 98.75 h from 2005 to 2011 during 400 boat surveys. Thirty-three dolphins were photo-identified, and their age and sex were estimated. The encounter rates, residency times, and group sizes were used to model the spatial distribution of dolphins with trammel nets and physiographic variables. Principal Component Analyses were applied to find the habitats selected for different behavioural activities. Encounter rates were significantly higher in early summer when trammel nets were more abundant. Residency times were spatially correlated to the mean number of trammel nets. Group sizes increased with distance from coast but decreased with abundance of trammel nets. Males preferred smaller groups than females, and groups with calves were larger than the other groups. Resting, socializing, and playing groups were larger than groups of dolphins engaged in travelling, foraging, and feeding. Spatial segregation between groups of dolphins with different sizes was observed. Although dolphins benefit from taking fish in trammel nets, this interaction can be dangerous because the fishermen can use harmful methods to deter dolphins from the net. Herein, we proposed that males prefer habitats where they have a higher probability of locating/capturing a desirable prey such as coastal areas with a greater amount of trammel nets; while for other activities, they may move into safer areas. On the contrary, females prefer habitats for reasons not associated with prey such as social behaviours, resting, or calf care/learning; and they may spend more time in the safest areas, at a distance from the coast, simply feeding when the opportunity presents itself. This study showed that group size/composition data are of critical importance for modeling dolphin-habitat relationships with significant consequences in terms of conservation strategies. [ABSTRACT FROM AUTHOR]

Interactions between bottlenose dolphins ( Tursiops truncatus) and fisheries are an increasing problem in the Mediterranean and effective management measures are needed. In order to assess the impact of dolphin interactions on artisanal trammel nets, we examine 354 fishing operations performed in waters of the Archipelago de La Maddalena (Italy). We evaluate whether interactions were related to the species composition of the catch and, using the local commercial value of the target species, we assess whether there was a real economic loss for fishermen. Bayesian models and partial correspondence analysis were used to determine the extent to which dolphin interactions and habitat differences contributed to variation in the species composition of catches. CPUE for fishing operations with no dolphin interactions was significantly higher than that for operations with dolphin interactions, although clearly this does not confirm a direct causal link, and associated economic loss was estimated to be non-significant. Geographic location, season, depth of seabed, moon phase, and mesh size were all important factors affecting the amount and species composition of the catch. Our results suggest that it is likely that these differences in species composition are due to a mixture of habitat and dolphin-induced effects. [ABSTRACT FROM AUTHOR]

The present study was conducted with trammel nets, which are intensively used in the Black Sea region, in order to investigate the influences of season, depth and mesh size on species composition and discard rates. In total, 27 species, belonging to 4 taxonomic groups (24 fish, 1 gastropod, 1 bivalve and 1 crustacean) were obtained. The percentage distribution of the total catch was 8.32% target species, 14.59% non-target landing and 77.09% discard. The discard rate ofMullus barbatusin the total catch was 0.61%. Among the total catch, Brachyura (22.74%) was the main group discarded, while the other important discard species wereRapana venosa(16.90%),Scorpaena porcus(13.71%) andUranoscopus scaber(9.65%). The lowest and highest discard rates were found in spring and autumn, respectively. According to depth, the lowest discard rate was from depths > 30 m (37.5%) and the highest at depths < 16 m (91.8%). Regarding the mesh size, minimum and maximum discard rates were obtained from 16 and 22 mm mesh sizes, respectively. According to one-way analysis of similarity (ANOSIM), there was a significant difference in discard species composition between spring and summer and between the < 16 m and > 30 m depth groups (P< 0.05). However, no significant difference was found between mesh size and discard composition (P> 0.05). [ABSTRACT FROM PUBLISHER]

For each Portuguese fleet component, landings of biogeographic groups of fish species were compared for the period of 1993-2009. Wide-distribution species were the most abundant in landings, but have shown a decreasing trend. Temperate species had higher landings in trawl fisheries, whereas subtropical species were most abundant and exhibiting an increasing trend in landings of multi-gear fisheries. A latitudinal gradient was observed, with landings of temperate species being more important in the North-western coast than in the South-western and South coasts. Although trawl fisheries were relatively more important in the North-western coast, there has been a recent increase in the relative importance of multi-gear fisheries and of subtropical species in this area. The increasing relative importance of subtropical species in Portuguese fisheries along with the fact that landings of subtropical species were higher in multi-gear fisheries could indicate an easier adaptation of Portuguese multi-gear fisheries to the effects of climate change. However, as multi-gear fisheries include a wide range of gears, techniques and target-species, they may not all respond in the same manner to changes in fish species' distribution. Among multi-gear fisheries, trammel nets catch a wider variety of species and a wider size range than gill nets or longlines; thus, trammel net fishers can adapt to changes in abundance of the main target species more readily than those using more species- and size-specific gears. Therefore, trammel net fisheries could more easily adapt to the effects of climate change on fish distribution than gill net or longline fisheries. [ABSTRACT FROM AUTHOR]

The aim of this study was to detect the rate and causes of loss of shrimp trammel nets, sole trammel nets and other gill and trammel nets during one fishing season in Iskenderun Bay, Turkey. Interviews with the captains of 127 fishing boats between November 2007 and November 2008 revealed the average effective loss rate per fishing boat for shrimp trammel nets, sole trammel nets and other gill and trammel nets as 4.33 ± 0.54, 5.35 ± 0.89 and 3.33 ± 0.34 panels, respectively, with a total loss of 723, 636 and 663 panels, respectively. The most common reason for shrimp and sole trammel net loss was conflict with other fishing gear; bad weather conditions were also reported as important reasons for losses of other gill and trammel nets. [ABSTRACT FROM AUTHOR]

Trammel nets are commonly used to sample rare fishes; however, little research has assessed delayed mortality associated with this capture technique. We conducted laboratory experiments to evaluate the effects of capture by trammel net on bonytail Gila elegans, razorback sucker Xyrauchen texanus, and roundtail chub Gila robusta, at 15, 20, and 25°C. Fish (139-288 mm total length) were entangled in a trammel net for 2 h or captured by seine net and then monitored for mortality for at least 14 d. Blood samples were collected immediately after capture, and plasma cortisol levels were quantified as an index of capture-related stress. The cortisol response varied by species, but mean cortisol levels were higher for fish captured by trammel netting (295.9 ng/mL) relative to fish captured by seine netting (215.8 ng/mL). Only one fish (of 550) died during capture and handling, but 42% of the trammel-netted fish and 11% of the seine-netted fish died within 14 d after capture. In general, mortality after capture by trammel net increased with increased water temperature and at 25°C was 88% for bonytail, 94% for razorback sucker, and 25% for roundtail chub. Delayed mortality of wild-caught fish captured by trammel net has the potential to be high, at least under some circumstances. We suggest that sampling frequency, timing of sampling (relative to reproductive cycles), and water temperature all be considered carefully when using trammel nets to sample diminished populations of imperiled native fishes. [ABSTRACT FROM AUTHOR]

Background. The fisheries of the Greek lagoons is based on the seasonal fish migration from coastal areas to the lagoon and the summer-to-winter offshore fish migration. The knowledge of the age and growth of the species in the two connected regions is essential for the proper management of the resources. The aim of this study was to estimate the age and growth of Liza aurata in the Messolonghi-Etoliko Lagoon system and the neighbouring coastal waters of the Gulf of Patraikos (Western Greece). Materials and methods. From December 1992 to February 1994, a total of 1146 individuals of Liza aurata were caught in the Klisova Lagoon (part of the lagoon complex of Messolonghi-Etoliko) and their adjacent sea coastal area, using barrier fish traps, seine, and trammel nets. The fish age was determined from scale readings. Back calculated lengths at age, as derived using scales readings, were used to estimate the growth parameters of von Bertalanffy equation. The length-weight relation was estimated by the equation: W = a ° Lb. Results. The total length (L) of examined specimens ranged from 9.7 to 59 cm. The scale readings revealed nine age classes in the Gulf of Patraikos (0 to VIII) and seven (0 to VI) in the lagoon. Maximum age was found to be 8 and 6 years for females and males, respectively. The analysis of the residuals sum of squares showed that the VBGF curves of sexes between the Patraikos sea area and the lagoon were not significantly different (sexes: F = 0.51, P > 0.05 and regions: F = 0.46, P > 0.05, respectively). The estimated values of VBGF for all samples were L8 = 65.08 ± 2.61 cm; k = 0.149 ± 0.017 year-1 and to = -1.15 ± 0.063 year. No significant difference on the length-weight relations among the sexes was found (F = 3.15, P > 0.05) while a significant difference on the length-weight relations among the regions (sea: W = 0.0036L3.26; lagoon: W = 0.0057L3.13) was found (F = 21.1, P < 0.05) which reproduced a rather low difference (<±5%) along the size (weight) of species. The length-weight relations exhibited allometry. Conclusion. The age and growth in length and weight of Liza aurata in the lagoon system of Messolonghi-Etoliko and the neighbouring seawaters of Gulf of Patraikos were not significantly different. This could be explained by the fact that the relative high salinity situation of the lagoon may rebut their high trophic advantage for the fish and/or alternatively, by a scenario that is based on the seasonal migrations of species between sea and lagoon. [ABSTRACT FROM AUTHOR]

Summary Under-or non-exploited areas are useful to aid in evaluating the potential productivity of fish stocks for sustainable fisheries. The Gulf of Castellammare (NW Sicily), where trawling has been banned since 1990, is a good site to study the biology and dynamics of low impacted fish populations. A total of 661 (595 female and 66 male) specimens of red mullet Mullus barbatus (95-245 mm total length, TL) obtained by monthly sampling from trammel net artisanal fishery, was collected in the Gulf of Castellammare from April 2006 to June 2007. Mature females occurred from April to September, with a peak in May. The mean Gonado-somatic index (GSI) also showed a May peak for both sexes. From Sagittae (642) readings the age structure ranged from age class I to VII in females and I to V in males. Female growth parameters, estimated according to the classic von Bertalanffy model, were: L∞ = 221.2 ± 11.51 mm standard error (SE), ky−1 = 0.38 ± 0.09 SE, t0y = −0.94 ± 0.38 SE. The growth performance index (ø' = 2.27) was included in the range of values obtained by hard structure readings in the Central Mediterranean. Natural mortality ( My−1) of females estimated by different methods ranged between 0.62 and 0.87 (mean value = 0.71 ± 0.06 SE). [ABSTRACT FROM AUTHOR]

Abstract: Long-term interannual changes in abundance, biomass, diversity and structure of littoral fish assemblages were examined between 1993 and 2009 by experimental trammel net fishing up to six times per year, within the warm period – May to September, at multiple areas along the eastern Adriatic coast with the aim of testing for the consistency of patterns of change across a large spatial scale (∼600 km). The results revealed spatially consistent increasing trends of total fish abundance and biomass growing at an average rate of 15 and 14% per year, respectively. Of the diversity indices analysed, the same pattern of variability was observed for Shannon diversity, while Pielou evenness and average taxonomic distinctness measures Δ∗ and Δ+ showed spatial variability with no obvious temporal trends. Multivariate fish assemblage structure underwent a directional change displaying a similar pattern through time for all the areas. The structural change in fish assemblages generally involved most of the species present in trammel net catches. A large pool of fish species responsible for producing the temporal pattern of assemblage change was relatively different in each of the areas reflecting a large geographic range covered by the study. An analysis of 4 fish species (Symphodus tinca, Pagellus erythrinus, Mullus surmuletus, Scorpaena porcus) common to each of the study areas as the ones driving the temporal change indicated that there were clear increasing trends of their mean catches across the years at all the study areas. A common pattern among time trajectories across the spatial scale studied implies that the factor affecting the littoral fish assemblages is not localised but regional in nature. As an underlying factor having the potential to induce such widespread and consistent improvements in littoral fish assemblages, a more restrictive artisanal fishery management that has progressively been put in place during the study period, is suggested and discussed. [Copyright &y& Elsevier]

Summary [ABSTRACT FROM AUTHOR]

The reproductive features of Spondyliosoma cantharus were studied in the Gulf of Tunis to contribute to better fisheries management on a regional scale and to broaden knowledge on whether there are actual performance differences compared to others areas. A total of 369 fish were caught by trammel and gill nets in the Gulf of Tunis from January 2005 to June 2006. Sex-ratio, gonad maturation, size and age at maturity, sexual cycle, condition and reproductive strategy were determined. The male : female ratio was initially skewed in favour of females, with males predominating in larger sizes. Length of females at first maturity was 17.8 cm TL (n = 141), which corresponds to 4 years of age. A recommendation is made to increase the length at capture. Spawning season extends from January to May, with a peak in March-April correlated to the lowest sea surface temperatures (14.8-15.6°C); during this period, a dichromatism arises between males and females. The hepatosomatic index and the condition factor present significant monthly changes in relation to the breeding activity. The bimodal size frequency distribution, the biased sex ratio, and the presence of bisexual gonads outline a protogynous hermaphroditism; diandry should be confirmed. [ABSTRACT FROM AUTHOR]

We analyzed the small-scale fishery in the port of Vilanova i la Geltrú (NW Mediterranean) to assess the fishing practices in this fishery and produce economic indicators of its status. We defined the fishing tactics (or métiers) of this fishery with a multivariate analysis approach for evaluating the main fishery resources and fishing gears employed. Our results show that netters in this fishery practice 7 types of fishing tactics. Five of these fishing tactics, in terms of target species, gear and seasonality, are also used in other small-scale Mediterranean fisheries. The main types of fishing gear (trammel nets, gillnets) and target species (Sepia officinalis, Solea vulgaris, Mullus surmuletus and Merluccius merluccius), and a well defined seasonality, are also observed in other studies of Mediterranean small-scale fisheries. We show that the seasonal rotation of fishing tactics is determined by the availability of different fish species rather than market price. Identifying the fishing tactics, which in the Mediterranean are relatively limited in number, of small-scale fisheries provides information for developing monitoring and management strategies for these fisheries. We also assessed the economic performance of the small-scale fishery in Vilanova i la Geltrú and its conflicts with other uses of the coastal zone. We conclude that small-scale fisheries are an economically viable activity although seriously threatened by concurrent uses of the coastal zone (conflict with other extractive activities; competition for space with tourism and leisure activities; pollution). The integrated management of the uses of the coastal zone is necessary in order to sustain small-scale fisheries, which have become less important in economic terms, but which are an important social component of local coastal communities and are a source of high quality seafood with a low ecological impact. [ABSTRACT FROM PUBLISHER]

Abstract: In 2008, Korean flounder (Glyptocephalus stelleri) was designated by the Korean Ministry for Food, Agriculture, Forestry and Fisheries as a species for restoration in the coastal waters of Korea. However, there are currently no regulations regarding the minimum landed size of flounder, or the minimum legal mesh size used by the coastal gillnet and trammel net fisheries. Selectivity experiments for gillnets and trammel nets were conducted using commercial vessels in several areas off the eastern coast of Korea between October 2006 and June 2009. The selectivity analysis required an adaption of the SELECT method because trammel net mesh sizes were altered part-way through the experiment. Gillnet and trammel net selectivity was best described using a bi-modal selection curve. The two gears were found to have different selection curves for a given mesh size. The length of maximum retention was similar for the two gears, but the selection curve of the trammel net was substantially wider than that of the gillnet. For the largest size of mesh used in the commercial fishery (8.5cm stretched), 50% relative retention was estimated to occur at a length of 20.4cm for the trammel net, and 22.5cm for the gillnet. In comparison, the length of 50% maturity for this species is approximately 26cm. As there are currently no size restrictions on landings of Korean flounder, these results suggest that use of these gears may pose a serious threat to local stocks of this species. [ABSTRACT FROM AUTHOR]

1. Trammel nets are one important cause of sea turtle mortality resulting from incidental capture. This study presents findings over a 10-year period during which loggerhead turtle by-catch in trammel nets, set off the central west coast of Sardinia (Italy) in the summer months, was recorded by 17 fishing vessels. 2. Since the by-catch registered represented counts of a rare event, data from the 17 vessels were used in the zero-inflated Poisson (ZIP) model to determine the abundance of turtle by-catch in trammel nets of the entire fleet, while a binomial generalized linear model was used to assess the probability of immediate survival for sea turtles incidentally caught in this gear. 3. The ZIP model quantified in about 45% the probability that 0.6 turtles have been caught by each vessel using trammel nets during summer over the 10-year period. In addition, the model estimated a total of 916 by-catch if the entire small-scale fleet was to use trammel nets in the study area in the summers between 1992 and 2001, with a direct mortality rate of 69%. 4. The probability of immediate survival for sea turtles caught in trammel nets seems to be directly related to the size of the specimens caught; however, this relationship is plausible only when incidental capture in the net occurs shortly before gear retrieval. 5. The study area represents a region where the abundance of sea turtle by-catch per vessel in trammel nets was much higher in July and August than in June and could represent a potential hot spot for the presence of juvenile loggerhead turtles, with high levels of interactions between the species and this fishing gear. Further research should better characterize the incidents of by-catch and assess potential innovative solutions that allow small-scale fisheries to coexist alongside sea turtles. [ABSTRACT FROM AUTHOR]

In this study, length and weight data are presented for 33 fish species inhabiting littoral habitats off the Yumurtalık coast. Samples were collected with combined gill and trammel nets. Parameters of the length-weight relationships were estimated for 14 species. The b values ranged between 2.35 and 3.53. For remained 19 species, the parameter a was estimated by setting b = 3.0. [ABSTRACT FROM AUTHOR]

Abstract: Elasmobranchs are an important bycatch component in Portuguese artisanal fisheries, but there are no management or monitoring programs in place yet. This study analysed elasmobranch catches in a Portuguese west coast trammel net fishery. Thirty-seven sampling surveys were conducted aboard commercial fishing vessels on a seasonal basis between October 2004 and August 2005. A total of 11 elasmobranch species were caught (seven Rajiformes, two Torpediniformes and two Carchariniformes), representing 4% of total catches and 15% of total weight. Raja clavata was the most important species in number (7.4ind 10,000m−1 of net) and Raja undulata the most important in weight (8512.4g 10,000m−1 of net). Discards represented 7.8% of total catch in weight, but 24.8% in number of specimens caught. Seven elasmobranch species were commonly discarded. There was a marked seasonality in elasmobranch catches, with lowest species richness registered in spring (four species) and highest in autumn (11 species). For the most abundant species depth range preferences were assessed. [Copyright &y& Elsevier]

Standardized monitoring programs in great rivers need to identify and minimize the bias in the estimates of fish population characteristics to enable fishery managers to make informed decisions. We compared the effectiveness of green and white mesh in drifted trammel and anchored gill nets in capturing fish in the Missouri River from downstream of Fort Randall Dam, South Dakota, to the mouth of the river near St. Louis, Missouri. Sampling occurred from March to November 2006 and from April to May 2007. Paired green and white trammel net drifts (N = 383) caught 28 fish species from 12 families. Pairs of anchored gill nets set overnight (N = 193) caught 24 fish species from 12 families Chi-square tests indicated that for most species there were no significant differences in occurrence between mesh colors in both the trammel and gill nets. However, occurrence was significantly higher in white mesh nets for goldeye Hiodon alosoides and blue sucker Cycleptus elongatus in trammel nets and for river carpsucker Carpiodes carpio and walleye Sander vitreus in gill nets. Despite turbidities in the Missouri River that ranged over two orders of magnitude, analysis of covariance indicated that water clarity had no significant effect on capture rates between green and white meshes. The majority of the variance in mean catch per unit e effort (CPUE) of these species in both gears was spatial or temporal. In general, CPUE and precision were either similar or higher for white nets, making it unnecessary to dye nets green, which saves time and money. Because turbidity did not significantly affect catch rates between green and white mesh nets, the variations in CPUE can more confidently be attributed to localized changes in the actual relative abundance throughout the Missouri River. [ABSTRACT FROM AUTHOR]

Abstract: In this work we studied an artisanal fishery targeting mainly soles (Solea senegalensis and Solea solea) and cuttlefish (Sepia officinalis) with trammel nets. Catches of target species, bycatches and discards were studied from October 2004 until August 2005 in the west coast of Portugal. A total of 37 sampling surveys onboard commercial fishing vessels were conducted. The number and weight of individuals of all species caught were registered, as well as the amount discarded and retained by fishermen. A total of 112 species were identified: Scomber japonicus, Chelidonichthys obscura and Callioynimus lyra were the most discarded fishes, corresponding to 28% in weight and 36% in number of discards. Discards represented 22%, in weight, of the total catches, while the amount retained by fishermen for consumption or direct selling was 12%, also in weight. The overall estimate of the annual discards value due to this fishery was ca. 170tonnes, comprising near 45 fishing vessels. Inconsistencies between the catches recorded onboard and the official landings were detected for the main target species. Some bycatches of species under recovery plans were also found. [Copyright &y& Elsevier]

Abstract: The loss of fishing gear has negative consequences to marine communities if the gear preserves its catching abilities for a significant period, a phenomenon called “ghost fishing”. The present study assessed the impact of lost trammel nets in both sandy and rocky bottoms in the central area of the Portuguese coast. Ten trammel nets, each 50m long and corresponding to the most common type used by the local commercial fleet, were allowed to fish continually for 285 days. During this time, changes in the structure and catching ability of each net were monitored by scuba divers in regular time intervals (1, 5, 10, 15, 20, 30, 40, 60, 80, 120, 250 and 285 days). Three control nets were also set in each bottom type the day before each monitoring dive. Irrespective of bottom type, nets’ fishing area decreased to about 40% during the first 30 days, and then gradually (rocky bottoms) or sharply (sandy bottoms). It was estimated that during the experiment 541 and 257 individuals were caught per 100m of net in rocky and sandy bottoms, respectively. Catching efficiency decreased in a negative exponential manner in parallel with the nets deterioration. The nets’ effective fishing lifetime, when catching efficiency became lower than 1%, was 10–11 months in the rocky bottom and 8 months in the sandy bottom. [Copyright &y& Elsevier]

Pallid sturgeon Scaphirhynchus albus and shovelnose sturgeon S. platorynchus are commonly sampled using drifting trammel nets in the Missouri and Mississippi river basins. Despite the fact that drifting trammel nets have been used for decades to sample these species, little is known about the capture efficiency of this gear. We estimated conditional capture probability for drifting trammel nets over known locations of pallid sturgeon and shovelnose sturgeon. In addition, we examined several variables that were predicted to influence the success of capturing a pallid sturgeon or shovelnose sturgeon in a drifting trammel net. Conditional capture probability (the conditioning factor was known presence) varied from 0.37 on the first attempt to 0.51 on the second attempt. None of the variables measured were useful in explaining the success of sampling a fish in a drifting trammel net. Drifting trammel nets are relatively efficient, and we suggest that they continue to be used to sample pallid sturgeon and shovelnose sturgeon in large turbid rivers. The high variability in catch per unit effort associated with sampling pallid sturgeon and shovelnose sturgeon using drifting trammel nets reported in the literature is probably related to the their low abundance (primarily pallid sturgeon) and patchy distribution (both species). Thus, using sampling designs appropriate for species with low abundance or patchy distributions rather than sampling designs commonly used for abundant species with ubiquitous distributions will require less effort because drifting trammel nets are relatively efficient. [ABSTRACT FROM AUTHOR]

A single adult female specimen of Halosaurus ovenii Johnson, 1864 was captured by trammel nets at a depth of about 200 m off the coast of Arbatax (Sardinia, Italy) in early April 2007. Macroscopic and microscopic analysis of the gonad showed a postspawning ovary. This is the fourth documented capture of this fish in the Mediterranean Sea, representing the north-easternmost record for this species in this geographic area. Furthermore, the present specimen was fished at the shallowest depth ever recorded before. [ABSTRACT FROM AUTHOR]

This study was carried out to determine the effects of harvesting method and refrigerated storage on biochemical composition of Atlantic Bonito. Samples were fish caught with a surround trammel net and a drift net in the Middle Black Sea region by fisherman and were brought to the laboratory. Quality control analyses for soluble solid, protein, fat and ashes were performed. On the 10th day after refrigerated storage (4C), pH, total volatile base nitrogen (TVB-N), trimethylamine (TMA-N) and thiobarbituric acid (TBA) values were found in the drift net. In the fresh fish samples caught by surround trammel net and drift net, fat, proteins, soluble solids and ash contents were calculated. PRACTICAL APPLICATIONS The results of the proximate content of Atlantic bonito caught with a trammel net and drift net showed that fat contents were 5.76; protein contents were 20.35; dry matter contents were about 30.5% and ash contents was 1–1.2%. After 10 days of storage at 4C, pH, TVB-N, TMA-N and TBA values were 6.17, 34.46 mg/100 g, 7.34 mg/100 g and 7.72 mg malonaldehyde/kg, respectively, in the surround trammel net, and 5.98, 40.60 mg/100 g, 8.02 mg/100 g and 8.03 mg malonaldehyde/kg in the drift net, respectively. Based on these results, there were significant differences between surround trammel net fishing and drift net fishing in terms of meat quality. [ABSTRACT FROM AUTHOR]

The results of 'trammel net' catches in a Mediterranean muddy-sandy bay, where two different anti-trawling artificial reefs (AARs) were located, are analysed in this study. Although the sampling was only carried out for two years and the only fishing gear used was the 'trammel net', a total of 45 species among chondrosteans and teleosteans were trapped. The two AARs, which were different in extension and for the shape of constructive items, have proven to be a useful tool for the protection of fish species, producing an increase both in terms of number and size of specimens, with a positive effect on biomass. These AARs also seem to favour the reappearance of species that had not been detected in the investigated area for many years. [ABSTRACT FROM AUTHOR]

Non-commercial invertebrate discards in an experimental trammel net fishery were studied in relation to selectivity of the gear, depth, soak time and season. Forty experimental fishing trials were carried out over a 1-year period with six combinations of small mesh (100, 120 and 140 mm) inner and large mesh (600 and 800 mm) outer panels. On average, 43.8 ± 12.2 (SD) (individuals 1000 m−1 of net) of non-commercial invertebrates were discarded, accounting for 48% and 65% of the total catch and total discards by numbers, respectively. Within non-commercial invertebrates discards, the six most abundant species by number were Phallusia mammillata (Cuvier) (27.5%), Cymbium olla (L.) (13.0%), Sphaerechinus granularis (Lamarck) (11.3%), Paracentrotus lividus (Lamarck) (10.9%), Astropartus mediterraneus (Risso) (8.2%) and Astropecten aranciacus (L.) (8.1%); Echinoderms (43.1%) particularly important. The highest and lowest discard ratios were found in autumn and winter, respectively. Discards generally decreased with depth, varied considerably in relation to soak time and were not related to mesh size combinations. Trammel nets seem to be the most important gear in terms of ecological impacts on benthic invertebrates compared with other coastal fishing gears and at the depths studied (15–60 m). [ABSTRACT FROM AUTHOR]

Abstract: Trammel net discards in four southern European areas were considerable, with a total of 137 species (79.7% of the total) discarded 65, 105, 46 and 32 species in the Basque country (Spain), Algarve (Portugal), Gulf of Cadiz (Spain) and Cyclades islands (Greece), respectively. The overall discard rate in terms of catch numbers ranged from 15% for the Cyclades to 49% for the Algarve, with the high discard rate for the latter due largely to small pelagic fishes. Discards in the four areas consisted mainly of Trisopterus luscus (Basque country), Scomber japonicus (Algarve), Torpedo torpedo (Cadiz) and Sardina pilchardus (all three areas), and Diplodus annularis in the Cyclades. Strong seasonal variation in discarding was found, reflecting differences in métiers and the versatility of trammel nets as a gear. Discarding, both in terms of numbers of species and individuals decreased with increasing inner panel mesh size. The main reasons for discarding were: (1) species of no or low commercial value (e.g. Scomber japonicus; Torpedo torpedo), (2) commercial species that were damaged or spoiled (e.g. Merluccius merluccius), (3) undersized commercial species (e.g. Lophius piscatorius), and (4) species of commercial value but not caught in sufficient quantities to warrant sale (e.g. Sardina pilchardus). A decrease in soak time together with the appropriate choice of mesh sizes could contribute to a reduction in discarding and to improved sustainability and use of scarce resources in the small-scale, inshore multi-species fisheries of southern Europe. [Copyright &y& Elsevier]

The objectives of this research were to evaluate the condition, size structure, and growth of shovelnose sturgeon ( Scaphirhynchus platorynchus) in the lower Platte River, Nebraska. A total of 1338 shovelnose sturgeon was collected using drifted gill and trammel nets (n = 954), trot lines (n = 340), and benthic trawls (n = 44) in the spring, summer, and autumn from four reaches: (i) Two Rivers State Park, (ii) confluence of Platte and Elkhorn rivers (iii) Louisville, Nebraska, and (iv) confluence of Platte and Missouri rivers during the spring, summer, and autumn of 2000 through 2004. Structural and condition indices were compared among reaches and years. Incremental relative stock densities (RSD) for shovelnose sturgeon sampled throughout the entire lower Platte River were: stock-quality (1), quality-preferred (12), preferred-memorable (82), and memorable-trophy (5). Proportional stock values were >99 for all years. A significance was detected in RSD categories among reaches and years with larger length-categories observed in the upstream reaches. Mean relative weight (W r) for all shovelnose sturgeon was 86.5, indicating a fit population. Mean W r showed no significant differences among years, but significance was detected among reaches and RSD categories. Shovelnose sturgeon in the lower Platte River appear to be in good condition and exhibit different length-frequency distributions longitudinally. [ABSTRACT FROM AUTHOR]

Discarding practices from 110 fishing operations in a Mediterranean small-scale fishing fleet (Patraikos Gulf, western Greece) from August 2004 to July 2005 were analysed. On average, 1 kg of fish was discarded per fishing operation (10% of the catch). The reasons for discarding were: low commercial value (78% of discards), damage at sea before retrieval of the gear (5%), and bad handling on-board (17%). More than half of discards belonged to Spicara flexuosa (L.), Lepidopus caudatus (Euphrasen), Sardinella aurita Valenciennes and Merluccius merluccius (L.). The bulk of discards of each species were associated with a single fishing method (metier). A Generalized Linear Model (Delta-X – error-model) indicated that, when discards were present, significant differences existed in the discard ratio among different métier groups (groups comprising métiers with similar characteristics). Longlines and trammel nets with small mesh-sizes had the highest discard ratios. Discarding practices for the species Diplodus annularis (L.), S. aurita, Squilla mantis (L.), S. flexuosa and Scorpaena scrofa (L.) did not follow a consistent pattern (these species were either fully discarded or fully retained during a fishing operation). The decision seemed to be dependent on market demands rather than fish size. Significant correlation was found between discarded and catch weight, but the presence of many outliers indicated deviance from a case where discards are high when there is an abundant catch. The findings of the study imply that monitoring and management should be carried out preferably on the métier level. Discards could be reduced by technical measures, controlling effort regulations and by improving working conditions on-board fishing vessels. [ABSTRACT FROM AUTHOR]

The green sturgeon, Acipenser medirostris, is a long-lived, iteroparous, anadromous acipenserid that is native to the San Francisco Bay Estuary, California. Sub-adult and adult fish are oceanic, but enter the estuary during the spring and remain through autumn. Little is known about green sturgeon distribution within the estuary or what, if any, physical parameters influence their movements. We report the results of a telemetry study conducted between September 2001 and November 2002. Five sub-adult and one adult green sturgeon were captured by trammel net in the San Pablo Bay region of the estuary. We implanted depth-sensing, ultrasonic transmitters within the peritoneum of individuals and tracked them from a boat for 1 – 15 h per day over periods ranging from 1 to 12 days. Salinity, temperature, and dissolved oxygen profiles of the water column were measured hourly. Observed movements were categorized as either non-directional or directional. Non-directional movements, accounting for 63.4% of observations, were closely associated with the bottom, with individuals moving slowly while making frequent changes in direction and swim speed, or not moving at all. Directional movements consisted of continuous swimming in the top 20% of the water column while holding a steady course for extended periods. Four of the five sub-adult fish remained within the confines of San Pablo Bay for the duration of their tracking period. The remaining sub-adult moved over 45 km up-river into Suisun Bay before contact was lost. The adult fish exited the bay and entered the ocean 6 h after release near Tiburon, CA, a movement of approximately 10 km. The sub-adult fish typically remained at the shallower depths (<10 m) of the estuary, but there were no apparent preferences for temperature, salinity, or dissolved oxygen, with the fish moving widely and rapidly across the range of these physical parameters. Activity is believed to be independent of light level with no discernable crepuscular, nocturnal, or diurnal peaks in activity. [ABSTRACT FROM AUTHOR]

Length–weight relationships for 47 coastal fish species from Gökceada Island in the northern Aegean Sea, Turkey are presented. Samples were caught in depths of <30 m by gill and trammel nets between March 2004 and February 2005. The most abundant families were Sparidae (30%), Centracanthidae (19.9%), Serranidae (7.14%), Scorpaenidae (6.59%) and Labridae (6.09%). Estimates for parameter b of the length–weight relationship ( W = aLb) ranged between 2.08 and 3.73. The mean b-value 3.03 ± 0.052 (SE) was not significantly different from 3. Significant differences between b-values were found between sexes for Boops boops, Diplodus annularis, Mullus surmuletus, Pagellus acarne, Sarpa salpa, Spicara maena and Spicara smaris and between seasons for Diplodus annularis, Mullus surmuletus and Spicara maena. [ABSTRACT FROM AUTHOR]

Research on ghost fishing became active in the late 1980s. Ghost fishing has been confirmed for traps, gillnets, trammel-nets and small seine nets. Some lost traps are functional for a long period of time, even in shallow waters. Consequences for gillnets after loss depend on seabed conditions. The ghost fishing function of gillnets remaining on flat seabeds declines rapidly with decreasing heights and increasing visibility. Gillnets left tangled around an artificial reef, for example, three-dimensionally maintain the initial magnitude of ghost fishing for a long period of time, even after badly fouled. There are increasing numbers of researches working on the total number of mortality per gear after gear loss for gillnets and trammel-nets. It has become also possible to estimate the total number of mortality for a unit period of time in a certain fishing sector. This paper reviews research which has provided evidence and quantitative data on ghost fishing, and proposes five items important for future studies on ghost fishing. [ABSTRACT FROM AUTHOR]

The size selectivity of plaice trammel nets was measured in an experiment using catch at length data from six different mesh sizes. Three trials at different times of the year were conducted on a traditional Danish gill-netter giving a total catch of 17,163 plaice—one of the largest European gill/trammel net datasets. Maximum likelihood procedure was used to estimate different types of selectivity curves for each set (soak). A bimodal curve was found to fit the data best. The between set variation was taken into account when calculating a mean selectivity curve for each of the three trials. The modal fish length for largest retention was 2.52 times mesh size. Significant seasonal differences in selectivity were found. The optimum mesh sizes were compared to commercial practice and the trammel net selectivity curve was compared to previous results on gill-nets with a low hanging ratio, i.e. tangle nets. [Copyright &y& Elsevier]