Geographical differences in the feeding patterns of red rockfish (Sebastes capensis) along South American coasts

Feeding habits and feeding strategy of red rockfish (Sebastes capensis) were studied from fish captured along most of the range of this species in coastal waters of South America. Stomach contents of 613 individuals, collected during 2003, were analyzed. Fish were obtained from six locations along the Chilean (23°S to 46°S) and Argentinian (43°S) coasts. The main prey items were Mysidacea (75.06% IRI), Osteichthyes (6.29% IRI),and Rhynchocinetes typus (6.03% IRI). Predator sex and size did not significantly affect the diet, but significant differences were found between locations. Four geographical areas, discriminated by prey occurrence and frequencies, were determined: three on the Pacific coast and one on the Atlantic coast. These areas correspond roughly with biogeographic zones described for the Chilean and southern Argentinian coasts. The feeding strategy index (FSI) indicated a specialized feeding strategy for S. capensis for most of its range. However, the FSI does not include the behaviour of a predator, and the FSI must be interpreted carefully for fishes like S. capensis that are passive ambush feeders. The abundance and availability of different prey may explain both the geographic differences in dietary composition and the specialized feeding strategy of S. capensis.

Spatial and temporal patterns in the bycatch of seabirds in the Argentinian longline fishery

Longline fisheries have grown throughout the world’s oceans for more than 40 years. This type of fisheries has captured high-quality fish (mature individuals rather than unwanted juveniles), has had minimal destructive effects on bottom habitats, and has produced a low bycatch of nontargeted fish (Brothers et al., 1999). Seabirds, however, are hooked accidentally when they swallow or are snagged on the baited hooks set by commercial longline crews (Brothers, 1991; Barnes et al., 1997; Tasker et al., 2000; Belda and Sanchez 2001; Jahncke et al., 2001

Population structure and variance effective size of red snapper (Lutjanus campechanus) in the northern Gulf of Mexico*

We assayed allelic variation at 19 nuclear-encoded microsatellites among 1622 Gulf red snapper (Lutjanus campechanus) sampled from the 1995 and 1997 cohorts at each of three offshore localities in the northern Gulf of Mexico (Gulf). Localities represented western, central, and eastern subregions within the northern Gulf. Number of alleles per microsatellite per sample ranged from four to 23, and gene diversity ranged from 0.170 to 0.917. Tests of conformity to Hardy-Weinberg equilibrium expectations and of genotypic equilibrium between pairs of micro-satellites were generally nonsignificant following Bonferroni correction. Significant genic or genotypic heterogeneity (or both) among samples was detected at four microsatellites and over all microsatellites. Levels of divergence among samples were low (FST ≤0.001). Pairwise exact tests revealed that six of seven “significant” comparisons involved temporal rather than spatial heterogeneity. Contemporaneous or variance effective size (NeV) was estimated from the temporal variance in allele frequencies by using a maximum-likelihood method. Estimates of NeV ranged between 1098 and >75,000 and differed significantly among localities; the NeV estimate for the sample from the northcentral Gulf was >60 times as large as the estimates for the other two localities. The differences in variance effective size could ref lect differences in number of individuals successfully reproducing, differences in patterns and intensity of immigration, or both, and are consistent with the hypothesis, supported by life-history data, that different “demographic stocks” of red snapper are found in the northern Gulf. Estimates of NeV for red snapper in the northern Gulf were at least three orders of magnitude lower than current estimates of census size (N). The ratio of effective to census size (Ne/N) is far below that expected in an ideal population and may reflect high variance in individual reproductive success, high temporal and spatial variance in productivity among subregions or a combination of the two.

Temporal and spatial distribution and abundance of flathead sole (Hippoglossoides elassodon) eggs and larvae in the western Gulf of Alaska

Data from ichthyoplankton surveys conducted in 1972 and from 1977 to 1999 (no data were collected in 1980) by the Alaska Fisheries Science Center (NOAA, NMFS) in the western Gulf of Alaska were used to examine the timing of spawning, geographic distribution and abundance, and the vertical distribution of eggs and larvae of flathead sole (Hippoglossoides elassodon). In the western Gulf of Alaska, flathead sole spawning began in early April and peaked from early to mid-May on the continental shelf. It progressed in a southwesterly direction along the Alaska Peninsula where three main areas of flathead sole spawning were indentified: near the Kenai Peninsula, in Shelikof Strait, and between the Shumagin Islands and Unimak Island. Flathead sole eggs are pelagic, and their depth distribution may be a function of their developmental stage. Data from MOCNESS tows indicated that eggs sink near time of hatching and the larvae rise to the surface to feed. The geographic distribution of larvae followed a pattern similar to the distribution of eggs, only it shifted about one month later. Larval abundance peaked from early to mid-June in the southern portion of Shelikof Strait. Biological and environmental factors may help to retain flathead sole larvae on the continental shelf near their juvenile nursery areas.

Impacto de las aguas residuales urbanas sobre las comunidades de macroalgas intermareales: caso practico en la Reserva de la Biosfera de Urdaibai

[ES] Las aguas residuales domésticas asociadas a los núcleos urbanos se encuentran entre los principales impactos antrópicos que amenazan la biodiversidad de los ecosistemas costeros. El presente trabajo tiene como objetivo evaluar el impacto de aguas residuales provenientes de la población de Bermeo sobre las comunidades intermareales de la parte mas externa de la Reserva de la Biosfera de Urdaibai. Para ello se ha contrastado la estructura de la vegetación bajo la influencia del emisario con la existente en cuatro localidades control en los años 2013 y 2014. Los resultados reflejan diferencias en la composición de la flora intermareal entre la localidad impactada y las localidades no afectadas por la contaminación. La localidad impactada queda caracterizada por la proliferación de algas filamentosas (Bachelotia antillarum) y clorófitos (Ulva intestinalis), así como de rodofíceas cespitosas con corticación simple (Gellidium pusillum, Gellidium pulchellum y Caulacanthus ustulatus). Por el contrario, en las localidades control son abundantes las especies perennes de gran porte y morfología compleja (Bifurcaria bifurcata, Cystoseira tamariscifolia, Halopteris spp. y Gelidium corneum). La calcárea Coralina elongata, estaba presente tanto en las localidades control como en la localidad impactada. Por otra parte, los análisis de la varianza realizados detectaron una elevada variabilidad espacio-temporal en la composición multivariable de la vegetación intermareal de las estaciones control, lo cual restó poder estadístico para detectar las diferencias entre la localidad impactada y los controles. Este resultado pone de manifiesto la dificultad e importancia de elegir controles apropiados para detectar impactos ambientales. Este estudio ha proporcionado la información necesaria sobre el estado ecológico de las comunidades en la situación pre-operacional de la EDAR de Lamiaran (Bermeo), lo cual permitirá evaluar en un futuro la eficacia del tratamiento de las aguas en términos de recuperación biológica.

Temporal and Spatial Distribution of Finfish Bycatch in the U.S. Atlantic Bottom Longline Shark Fishery

Bycatch in U.S. fisheries has become an increasingly important issue to both fisheries managers and the public, owing to the wide range of marine resources that can be involved. From 2002 to 2006, the Commercial Shark Fishery Observer Program (CSFOP) and the Shark Bottom Longline Observer Program (SBLOP) collected data on catch and bycatch caught on randomly selected vessels of the U.S. Atlantic shark bottom longline fishery. Three subregions (eastern Gulf of Mexico, South Atlantic, Mid-Atlantic Bight), five years (2002–06), four hook types (small, medium, large, and other), seven depth ranges (<50 m to >300 m), and eight broad taxonomic categories (e.g. Selachimorpha, Batoidea, Serranidae, etc.) were used in the analyses. Results indicated that the majority of bycatch (number) was caught in the eastern Gulf of Mexico and that the Selachimorpha taxon category made up over 90% of the total bycatch. The factors year followed by depth were the most common significant factors affecting bycatch.

Variabilidade espacial e temporal das concentrações de clorofila na Baía de Guanabara (RJ) utilizando imagens MERIS e dados in situ

Este trabalho teve como objetivo principal implementar um algoritmo empírico para o monitoramento do processo de eutrofização da Baía de Guanabara (BG), Rio de Janeiro (RJ), utilizando dados de clorofila-a coletados in situ e imagens de satélite coletadas pelo sensor MERIS, a bordo do satélite ENVISAT, da Agência Espacial Européia (ESA). Para a elaboração do algoritmo foi utilizada uma série histórica de clorofila-a (Out/2002 a Jan/2012) fornecida pelo Laboratório de Biologia Marinha da UFRJ, que, acoplada aos dados radiométricos coletados pelo sensor MERIS em datas concomitantes com as coletas in situ de clorofila-a, permitiu a determinação das curvas de regressão que deram origem aos algorítmos. Diversas combinações de bandas foram utilizadas, com ênfase nos comprimentos de onda do verde, vermelho e infra-vermelho próximo. O algoritmo escolhido (R = 0,66 e MRE = 77,5%) fez uso dos comprimentos de onda entre o verde e o vermelho (665, 680, 560 e 620 nm) e apresentou resultado satisfatório, apesar das limitações devido à complexidade da área de estudo e problemas no algoritmo de correção atmosférica . Algorítmos típicos de água do Caso I (OC3 e OC4) também foram testados, assim como os algoritmos FLH e MCI, aconselhados para águas com concentrações elevadas de Chl-a, todos com resultados insatisfatório. Como observado por estudos pretéritos, a Baia de Guanabara possui alta variabilidade espacial e temporal de concentrações de clorofila-a, com as maiores concentrações no período úmido (meses: 01, 02, 03, 10, 11 12) e nas porções marginais (~ 100 mg.m-3), particularmente na borda Oeste da baia, e menores concentrações no período seco e no canal principal de circulação (~ 20 mg.m-3). O presente trabalho é pioneiro na construção e aplicação de algoritmos bio-óptico para a região da BG utilizando imagens MERIS. Apesar dos bons resultados, o presente algorítmo não deve ser considerado definitivo, e recomenda-se para trabalhos futuros testar os diferentes modelos de correção atmosférico para as imagens MERIS.

Spatial and Temporal Distribution of Sea Turtles in the Western North Atlantic and the U.S. Gulf of Mexico from Marine Recreational Fishery Statistics Survey (MRFSS)

Systematic surveys, along with opportunistic sightings, have provided important information on sea turtle (Cheloniidae and Dermochelydae) distributions, knowledge which can help reduce the risk of harmful human interaction. In 1991 and 1992, the Marine Recreational Fishery Sta- tistics Survey (MRFSS) of the National Ma- rine Fisheries Service, NOAA, provided a unique opportunity to gain additional, synoptic information on the spatial and temporal distribution of sea turtles along the U.S. Atlantic and Gulf of Mexico coasts by asking recreational anglers if they had observed a sea turtle on their fishing trip. During the spring and summer months of those years, as water temperatures warmed, the MRFSS documented an increase in sea turtle sightings in inshore waters and in a northward direction along the U.S. Atlantic Coast and in a westward direction along the northern Gulf of Mexico. This pattern reversed in the late summer and fall months as water temperatures cooled, with sea turtles concentrating along Georgia and both coasts of Florida. Although the MRFSS did not provide species or size composition of sea turtles sighted, and effort varied depending upon location of fishing activity and time of year anglers were queried, it did provide an additional and useful means of ascertaining spatial and temporal distributions of sea turtles along these coasts.

Preliminary Analysis of the Feasibility of Transferring New Longline Technology to Small Artisanal Vessels off Northeastern Brazil

The catches of three longliners, including two recently converted small artisanal vessels and one large leased foreign longliner, were compared to provide some indication of the feasibility of transferring new longline technology to small vessels in the northeastern Brazilian pelagic longline fishery. Comparisons of catches between the two recently converted vessels operating across the same spatial and temporal scales showed no significant differences for the main target species, providing evidence to suggest that adoption of the technology was rapid and straightforward. A comparison of relative catch rates between one of the recently converted small longliners and the leased longliner across the same temporal scale, but in different areas, showed that while there were significant differences detected for some species, contributing to a significant reduction in total CPUE, the relative abundance of commercially important species within the operational range of the smaller vessels was sufficient for economically viable catches. The results showed that the net financial profit from the artisanal longliner was almost 10 times greater than that derived from existing fishing methods. The inclusion of some artisanal vessels in this fishery may help address the social and economic problems currently faced by fi

Curso temporal dos efeitos da exposição à nicotina durante a lactação no sistema colinérgico cerebral de ratos

A Organização Mundial da Saúde estima que existam aproximadamente 250 milhões de mulheres tabagistas no mundo. Em países em desenvolvimento, a prevalência do tabagismo pode variar de 11 a 35% em mulheres grávidas, constituindo um problema de saúde pública. Nicotina, um agonista colinérgico considerado o mais importante componente ativo da fumaça do cigarro, é capaz de causar déficits em um cérebro em desenvolvimento, no entanto, muitos estudos investigam estes efeitos durante a gestação de roedores, que corresponde aos dois primeiros trimestres de gestação em humanos. O presente estudo, foi focado nos efeitos da nicotina sobre o sistema colinérgico cerebral durante o equivalente ao terceiro trimestre de gestação em humanos. Ratas lactantes foram expostas a nicotina (NIC, 6 mg/Kg/dia) ou a salina (SAL) via mini-bombas osmóticas (s.c.) a partir do 2 dia ate o 16 dia pós-natal (PN). Filhotes NIC e SAL foram sacrificados durante a exposição, em PN15, e após a retirada em três momentos diferentes, PN21, PN30 e em PN90. Quatro biomarcadores foram considerados. Para avaliação dos efeitos sobre os receptores nicotínicos de acetilcolina (nAChRs), nós utilizamos [3H]citisina, que é um ligante seletivo para α4β2. Nos também medimos o marcador [3H]hemicholinium-3 (CH-3) de alta afinidade para o transportador pré-sináptico de colina, e a atividade das enzimas colina acetiltransferase (ChAT) e acetilcolinesterase (AChE) no córtex cerebral (CX), mesencéfalo (MB) e hipocampo (HP) na prole. O grupo NIC apresentou supra-regulação de nAChRs em todas as regiões durante a exposição, este efeito foi revertido pouco tempo após a retirada. Interessantemente, uma significante infra-regulação de nAChRs foi observada após um longo tempo da retirada somente em CX. A exposição à nicotina reduziu a marcação para HC-3 durante a exposição em todas as regiões e foi revertida em PN21. Já em PN30, o grupo NIC apresentou uma diminuição do HC-3. Em contraste, em PN90, foi observado um aumento de HC-3. Não foram observados efeitos para atividade da ChAT e da AChE em CX. No que diz respeito ao MB, o grupo NIC apresentou um aumento de atividade para ambas as enzimas, ChAT e AChE, em PN30. Para a mesma idade, nos observamos um decréscimo desta atividade somente em HP. E, após um longo tempo de retirada, somente HP apresentou um aumento na atividade da ChAT. Estes dados sugerem que a exposição à nicotina em ratos durante o equivalente ao terceiro trimestre de gestação em humanos promove alterações no sistema colinérgico dos filhotes. Somado a isto, nossos resultados indicam que os efeitos prejudiciais são observáveis mesmo muito tempo após a exposição ter sido interrompida.

Temporal Changes in a Tropical Nekton Assemblage and Performance of a Prawn Selective Gear

The temporal variation of components of a moderately diverse (H=1.46) tropical estuarine fish assemblage (long. 146°30'E, lat. 8°45'S) was directed by salinities that had been determined by local oceanographic and probably topographic conditions. For this assemblage, two types of intrayear component profiles are predicted. Pooled data (1988-91) reveal a large component of regular/resident species (43%) in an assemblage which has been under a narrow temperature regime «5T). These results facilitate a discussion on the relevance and usefulness of three hypotheses often cited in studies concerning species diversity and component characteristics of the subtropical/tropical coastal nonreef fish assemblages. Manifestations of the assemblage are reflected in catch composition and weights of 39 trials conducted for a selective prawning gear whose performance in bycatch reduction, mainly for finfishes, is judged by an index, E, we have previously proposed. This gear is capable of harvesting the prawn while conserving the demersal fish. Behavioral responses to netting of the prawns and the finfishes, especially the nearshore surface schoolers such as leiognathids, are discussed from several points of view. An adaptation in terms of group selection for leiognathids of their locking mechanism of median fin spines has been interpreted. For the purpose of bycatch reduction or E enhancement, suggestions for improvements in net design and trawl configuration by considering the behavioral features of fish are made. Our original formula of E is modified for general use. Bycatch problems in the regional prawn fisheries and their possible impacts on fishery planning and development in Papua New Guinea as a developing country are discussed. The gear tested may offer enormous ecological and economic benefits. The gear is multipurpose, extremely simple, and can also be used as a biological sampler.

Temporal and Spatial Distribution of Catches of Tiger Sharks, Galeocerdo cuvier, in the Pelagic Longline Fishery Around the Hawaiian Islands

Thirty-five tiger sharks, Galeocerdo cuvier, have been reported caught in pelagic longline gearfrom 25 to 265 n.mi. off the Hawaiian Archipelago during December 1990-May 1993. Fifteen sharks were caught farther than 50 n.mi. offshore, indicating that tiger sharks do occur well offshore and removed from benthic topography. About 89% of the sharks were caught during October-March, while only 56% of the fishing effort occurred during that period.