Fisheries

Reef fish populations are conspicuous and essential components of coral reef ecosystems, but monitoring strategies have historically varied across agencies in their objectives and designs. An unprecedented multi-agency reef fish monitoring effort involving NOAA Fisheries, the University of Miami, the National Park Service and the Florida Fish and Wildlife Conservation Commission was initiated across the Florida coral reef ecosystem in 2008. This collaboration builds directly upon a large-scale fisheries-independent survey that began in 1979. The methods are directed to address precipitous declines in fishery resources, understand variability in natural processes, and to evaluate new ecosystem-based management tools like MPAs. There is significant motivation to address the biological, political, economic, and legal issues of these objectives through a shared vision for monitoring and assessment. In this study, precise and cost-effective sampling was achieved by collaborative surveyin...

Vidal, E. A. G., Haimovici, M., and Hackbart, V. C. S. 2010. Distribution of paralarvae and small juvenile cephalopods in relation to primary production in an upwelling area off southern Brazil. – ICES Journal of Marine Science, 67: 1346–1352. The distribution of paralarvae and small juvenile cephalopods sampled by a rectangular midwater trawl (opening area 8 m2) over the continental shelf off Cape Santa Marta Grande, southern Brazil (28°09′S–29°56′S) during spring 1989 is discussed. An intrusion of Brazil Current Tropical Water (22°C; 36.5) separates warm, less-saline water (22°C; 35.2) from cooler, more-saline water (15°C; 36.4). Prevailing northeasterly winds led to upwelling of South Atlantic Central Water over the shelf, promoting high Chl a concentrations. Three species constituted 99% of the 628 cephalopods collected: Illex argentinus (n = 540; 4–40 mm mantle length, ML), Argonauta nodosa (n = 46; 2–19 mm ML), and Loligo sanpaulensis (n = 42, 2–21 mm ML). Segregation of I. ar...

Ocean grabbing occurs when traditional users, such as small-scale fishers, are pushed aside by new development activities. This grabbing must be prevented to avoid sea uses that maintain or increase social inequity. In this paper, we show that in tropical Atlantic countries, such as Brazil and Senegal, examples of ocean grabbing already occur. In this context, we analyse if Maritime Spatial Planning (MSP) may be an opportunity to limit ocean grabbing or, to the contrary, poses a risk to increase it. MSP calls for an ecosystem approach that requires integrated coastal and marine management and involves stakeholders in developing a shared vision of the future, where society and environment are preserved. However, recent studies have shown that MSP is a process to be used cautiously to ensure equitable decisions. Meanwhile, the concept is spreading worldwide including in tropical Atlantic countries. We highlight that context matters and the specificities of the tropical Atlantic must b...

The shortfin mako is one of the most important shark species caught in Atlantic Ocean pelagic fisheries. Given increasing concerns for the stock status of the species, the present study was designed to fill gaps in the knowledge of habitat use and movement patterns of shortfin mako in the Atlantic Ocean. From 2015 to 2019, 53 shortfin makos were tagged with pop-up satellite archival tags within the North, Central, and Southwest Atlantic Ocean, with successful transmissions received from 34 tags. Generally, sharks tagged in the Northwest and Central Atlantic moved away from tagging sites showing low to no apparent residency patterns, whereas sharks tagged in the Northeast and Southwest Atlantic spent large periods of time near the Canary Archipelago and Northwest Africa, and over shelf and oceanic waters off southern Brazil and Uruguay, respectively. These areas showed evidence of site fidelity and were identified as possible key areas for shortfin mako. Sharks spent most of their ti...

This study analyses depredation by killer whales (Orcinus orca) and false killer whales (Pseudorca crassidens) on catches of the Uruguayan pelagic longline fishery in the Southwestern Atlantic Ocean between 1998 and 2007. Data were collected by scientific observers from the National Observer Program of the Tuna Fleet operating in the area between 19°–40.5°S and 20°–54°W. Depredation occurred in 67 of the 1029 sets and was restricted to the area from 25°–40.5°S to 27°–53°W, though larger proportions of depredation (DP: percentage of total fish caught damaged by cetaceans) were observed in the Brazil–Malvinas (Falkland) Confluence area (34°–37°S and 51°–53°W) where most of the fishing effort was concentrated. Depredation occurred year-round though intra-annual variability in its intensity was recorded. The overall DP was 0.37% and was slightly higher in autumn. The spatial analysis showed that DP within grids of 1 × 1° was homogeneous and generally <2.5%. Ten out of 57 fish species...

Inventory and monitoring of coastal aquaculture and fisheries structures provide important baseline data for decision-making in planning and development, including regulatory laws, environmental protection and revenue collection. Mapping these structures can be performed with good accuracy and at regular intervals by satellite remote sensing, which allows observation of vast areas, often of difficult accessibility, at a fraction of the cost of traditional surveys. Satellite imaging radar (SAR) data are unique for this task not only for their inherent all-weather capabilities, very important as aquaculture activities mainly occur in tropical and subtropical areas, but essentially because the backscatter from the structure components allows for their identification and separation from other features. The area selected and object of the study has been Lingayen Gulf, sited in northwestern Luzon Island, the Philippines, where all these structures of interest occur. Field verification of ...

The present study was conducted to determine the fish fauna of Satluj River at Mailsi Syphon, situated in South Punjab Pakistan. The survey was conducted from 2012 to 2013 at selected sampling sites (both upstream and downstream) to discover fish diversity and their distribution pattern. The ichthyofauna observed during the study; 18 fish species that were categorized into seven families and six orders. In terms of fish species, Cyprinidae was the dominant family which includes the following eight species: Gibelion catla, Cirrhinus mrigala, Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, Labeo calbasu, Labeo rohita and Macrotepis putitora. The present study was useful in providing the baseline information on species distribution and diversity. The work was initiated to make the checklist of fish fauna of River Satluj at Mailsi Syphon; one of the neglected site by researchers. If prompt and relevant mitigation measures will not adopted, the biodiversity of the ...

Reports from 637 fish kills that occurred between 1984 and 2002 in Florida canals (n = 264), creeks/rivers (n = 64) and ponds/lakes (n = 309) were examined to assist manage-ment agencies that need to understand and respond to fish kill events. Critical investigation of 407 fish kills showed that 75% were caused by probable natural processes, 13% were from unknown causes, and 12% were human-induced. Fish kills occurred in every month of the year but were most abundant in summer from June through September as was the abundance of rainfall and warmer water temperatures. Canals, creeks/rivers, and ponds/lakes showed strong signif-icant correlations (p < 0.05) between average monthly rain-fall and monthly frequency of fish kills with correlation coefficients of 0.86, 0.73, and 0.72, respectively. The Florida lakes that had fish kills, where water chemistry data were available (n = 25), tended to be alkaline with mean pH and alkalinities of 7.7 and 55 (mg/l as CaCO 3), respectively. Th...

This research focuses on the critical issue of biodiversity loss, primarily caused by the misidentification of economically important fish species. Fish samples were obtained at three stations twice in a month from November 2022 to September 2023 with the aid of local fishers using gill nets and cast nets for ecological studies of important fish species of Bonny River, Okrika LGA, Rivers State, Nigeria. The sampling results showed a total composition of 23,102 individuals belonging to six (6) orders, twelve (12) families, fourteen (14) genera and nineteen (19) species which were identified using a combination of DNA barcoding using mitochondrion cytochrome oxidase subunit I (COI) gene marker and morphological method. The tissue samples for 8 species (Pseudotolithus senegallus, Pseudotolithus typhus, Pseudotolithus elongatus, Pangasius polyuranodon, Chrysichthys nigrodigitatus, Neochelon falcipinnus, Coptodon guineensis and Lutjanus aratus) were excised, DNA isolated, amplified and sequenced. Cichlidae showed the highest diversity of 31.41% with three (3) species, Sciaenidae had a diversity value of 24.42% with three species and the remaining 10 families below 10%. Fish diversity was observed to be higher in January 2023 with 19 fish species and lowest in September 2023 with 9 fish species. The Berger-Parker's dominance (d) ranged from 0.01 to 0.31 depicting the dominance of a few species. Simpson's diversity index ranged from 0.90 to 0.99. The study highlights that the high fish diversity in specific species and families within the Bonny River may be attributed to inadequate managerial practices in Bonny fisheries.