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The temperature in the South Atlantic underwent an increase from 1948 to 2016, and the Brazilian coast is very likely suffering from climate change. We examined temporal shifts in the abundance of the fish fauna that inhabit shallow waters and aimed to associate these shifts with climate effects. We selected candidate species according to changes in their relative abundance over four decades (1980s, 1990s, 2000s, 2010s) in a transition area between the tropical and subtropical regions in southeastern Brazil. Forty-seven species exhibited changes in abundance during the study period. Several small pelagic/planktophagous clupeoids (Anchoa lyolepis, Anchoa tricolor, Harengula clupeola, and Sardinella brasiliensis) reacted strongly to climate change with rapid population growth, whereas others (Anchoa marinii, Anchoviella brevirostris, Anchoviella lepidentostole, and Lycengraulis grossidens) decreased in relative abundance or disappeared. Some tropical species appear to be moving to this transition zone (e.g., Achirus lineatus, Ctenogobius boleosoma, and Haemulopsis corvinaeformis) because they appeared or increased populations. Conversely, subtropical species (e.g., Genidens barbus, Platanichthys platana, Boridia grossidens, and Trachinotus falcatus) decreased populations or disappeared, probably moving southward to more favorable areas, consistent with warming. This is the first estimation of climate change impacts on the southwestern Atlantic nearshore fishes and contributes as support for management policies. [ABSTRACT FROM AUTHOR]

Fluxes of nutrients across habitats are of paramount relevance in ecological studies due to the implication in primary production, trophic structure and biodiversity. This study analyses the role of sandy beaches in the processing of organic matter. Three beaches with different macroalgal inputs were sampled throughout the annual cycle. The standing stock of wrack macroalgae on the beach surface and the nutrient concentration in the intertidal pore water (IPW) and in the surf zone water were measured monthly. Mean concentration of dissolved inorganic nitrogen and phosphate in the IPW increased from the low to the very high subsidized beach. Seasonal coupling was observed between the wrack biomass and the nutrient concentration throughout the year. Among the nutrient species, a variable relationship was found between the NH/NO ratio and the biomass of macroalgae deposited. These results provide evidences of the active role of sandy beaches in the processing of organic matter and in the nutrient cycling, remarking the feedback connectivity between sandy beaches and their neighbour ecosystems. [ABSTRACT FROM AUTHOR]

Factors such as nutritional quality and the secondary metabolite content of food resources have been shown to influence the feeding behavior of herbivores in many marine habitats. For intertidal macroalgae consumers on sandy beaches, the influence of these factors on feeding behavior and the consequences on their performance is poorly understood. In this study, we evaluated the relationships of nutritional quality, chemical defenses (phlorotannins), and the structure of three macroalgal species that form the bulk of imported wrack subsidies to beaches in southern Chile, with the feeding behavior, absorption efficiency, and growth rate of the talitrid amphipod Orchestoidea tuberculata, one of the most abundant organisms in this environment. The amphipods preferred Durvillaea antarctica over Lessonia nigrescens and Macrocystis pyrifera when simultaneously offered fresh pieces of each alga. Similar results were observed when artificial food made of dry powdered algae of each species was provided, suggesting that the structure of these three algae did not influence preference. The performance of amphipods when reared on a diet of a single algal species matched feeding preferences; higher growth rates were observed in treatments with the preferred alga, D. antarctica. These results imply that D. antarctica is a superior food item for O. tuberculata when compared to L. nigrescens or M. pyrifera, and also that the alga’s intrinsic quality (i.e., not structure) may influence dietary preference in these consumers. The higher content of proteins and carbohydrates found in D. antarctica may explain why this macroalga represents better quality food for O. tuberculata. Phlorotannin content did not have obvious negative effects on diet choice or growth, as D. antarctica, the alga with greater content of these secondary metabolites, was preferred and associated with higher growth rates of O. tuberculata. However, it is necessary to emphasize that the low phlorotannins concentrations registered in the three macroalgae species examined in this study, may not have been sufficient to deter O. tuberculata. When the amphipods were fed with each alga individually, they consumed significantly higher quantities of D. antarctica, which suggests that O. tuberculata did not eat more to compensate for the lower nutritional quality of the other algal species in order to maintain growth. Nor was compensation for lower food quality achieved by increasing absorption efficiency. Our results imply that the composition of the macroalgae arriving on the beach can significantly affect the performance and subsequent life history traits of O. tuberculata and by extension other amphipod species. [ABSTRACT FROM AUTHOR]

Six sandy beaches on the North West coast of Spain, exposed to different wave action, were sampled in order to study the macroinfauna community and the biopolymeric fraction (proteins, lipids and carbohydrates) of sedimentary organic matter. According to McLachlan’s rating system (1980), three of them were classified as sheltered and the other three as exposed beaches. Sampling was carried out during August 2004 at three tidal levels: high, medium and low. Macroinfauna community and organic matter concentrations were found to be significantly different when sheltered and exposed beaches were compared. Macroinfauna diversity (H′), abundances and biomass became increasingly enriched along a gradient from exposed to sheltered beaches. Macroinfauna mean abundance was found higher in sheltered (ranked from 1535 ± 358 to 15062 ± 5771 ind m−2) than in exposed beaches (from 150 ± 41 to 5518 ± 1986 ind m−2). Macroinfauna biomass ranged from 3.2 to 14.7 g m−2 and species richness from 25 to 27 in sheltered localities; while in exposed beaches, biomass ranged from 0.2 to 2.3 g m−2 and the number of species from 5 to 14. The biopolymeric carbon concentration (BPC) was significantly higher in sheltered (from 84.7 ± 44.7 to 163.3 ± 34.8) than in exposed (from 30.3 ± 7.5 to 78.7 ± 12.3) beaches. The low hydrodynamic conditions of sheltered beaches favoured the settlement of organic rich fine sediments, being supported by the higher protein to carbohydrate ratio found in the exposed (from 23.5 ± 0.9 to 32.7 ± 4.4), rather than in the sheltered localities (from 6.2 ± 0.7 to 13.6). Mean macroinfauna abundances were higher at medium and low tidal levels in both sheltered and exposed beaches. Crustacea was found to be the main group inhabiting the upper part of both types of beaches, dominating all tidal levels of exposed sandy beaches. Mollusca and Polychaeta groups were dominant in sheltered beaches at the medium and lower levels. There was a significant negative relationship between the BPC and the beach face slope; thus, BPC decreased as the intertidal slope increased. It seems that exposed sandy beaches are mainly physically controlled, whereas hospitable sheltered beaches let other factors, such as biochemical compounds, enrich the benthic fauna scenery. [ABSTRACT FROM AUTHOR]

Two new species of mysid shrimps are described from shallow coastal waters of Northern Oman. Haplostylus quadrispinosus sp. nov. is primarily distinguished from allied species by the arrangement and size of lateral spines on the telson. The form of the telson and exopod of the 4th male pleopod characterize a second new species, Anisomysis arabica sp. nov. A third species Mysidopsis kenyana, was previously recorded only from East Africa and its presence in samples considerably extends its geographical distribution. Four mysid species are now documented from coastal waters of Oman. [ABSTRACT FROM AUTHOR]

Sampling for mysid shrimps in shallow coastal waters of Mozambique provided new distribution records for Siriella brevicaudata Paulson, 1875, Gastrosaccus bispinosa Wooldridge, 1978, Gastrosaccus longifissura Wooldridge, 1978, Dioptromysis proxima Nouvel, 1964 and Anisomysis maris rubri Bãcescu, 1973. Rhopalophthalmus tropicalis sp. nov. and Gastrosaccus mozambicus sp. nov. are described for the first time. The former species is distinguished from its closest relative R. terranatalis O. Tattersall, 1957 by its much smaller size, the lack of serrations on the lateral spines of the telson, the structure and arrangement of the spines on the antennal sympod and the number of subdivisions of the propodus of the thoracic endopod. Adult males of G. mozambicus sp. nov. show affinity to G. bispinosa, but the two species are separated by the form of the two distal exopod segments on the 3rd pleopod. [ABSTRACT FROM AUTHOR]

Patterns in composition, abundance and diversity of the annelid fauna (Polychaeta and Oligochaeta) in 22 sandy beaches in Iceland were explored. The effect of exposure on annelid distribution was studied. A total of 5651 annelids were recorded from 160 core samples. Oligochaetes (chiefly Tubificidae) dominated the annelid assemblage whereas polychaetes represented a minor fraction. Polychaetes were relatively more abundant in exposed than in sheltered beaches, contrary to oligochaetes. Meiofaunal polychaete species were also more abundant in exposed than in sheltered beaches. Southwest beaches seemed more diverse in annelid species than northern ones. Annelid diversity did not differ between sheltered and exposed sites, but higher diversity was attained in fine sands at sheltered areas. Cluster analysis revealed large differences between beaches in the annelid community composition. The general patterns found suggest that beach exposure is a major factor conditioning macro- and meiofaunal polychaete and oligochaete distribution along the Icelandic coast. [ABSTRACT FROM AUTHOR]