Background Articles

Guyana’s fish production has suffered a significant decline partly due to the adverse impact of sargassum seaweed, local and regional fishery experts said.

The regionally endemic Galapagos Grouper, locally known as bacalao, is one of the most highly prized finfish species within the Galapagos Marine Reserve (GMR). Concerns of overfishing, coupled with a lack of fishing regulations aimed at this species raises concerns about the current population health. We assessed changes in population health over a 30-year period using three simple indicators: (1) percentage of fish below reproductive size (Lm); (2) percentage of fish within the optimum length interval (Lopt); and (3) percentage of mega-spawners in the catch. Over the assessed period, none of the indicators reached values associated with healthy populations, with all indicators declining over time. Furthermore, the most recent landings data show that the vast majority of the bacalao caught (95.7%,) were below Lm, the number of fish within the Lopt interval was extremely low (4.7%), and there were virtually no mega-spawners (0.2%). Bacalao fully recruit to the fishery 15 cm below the size at which 50% of the population matures. The Spawning Potential Ratio is currently 5% of potential unfished fecundity, strongly suggesting severe overfishing. Our results suggest the need for bacalao-specific management regulations that should include minimum (65 cm TL) and maximum (78 cm TL) landing sizes, slot limits (64–78 cm TL), as well as a closed season during spawning from October to January. It is recognized that these regulations are harsh and will certainly have negative impacts on the livelihoods of fishers in the short term, however, continued inaction will likely result in a collapse of this economically and culturally valuable species. Alternative sources of income should be developed in parallel with the establishment of fishing regulations to limit the socio-economic disruption to the fishing community during the transition to a more sustainable management regime.

B.C salmon farms last year were besieged by sea lice, according to a new University of Toronto study, which also found a dangerously steep rise of infestation among young wild salmon who swam nearby.

The latest research suggests pink salmon could be depriving offshore coho and chinook of squid.

Populations of marine wildlife have plummeted by a half on average over the past 40 years with some species suffering far greater declines as a result of habitat loss, overfishing, rising sea temperatures and worsening ocean acidity, a major report has found.

If you're wondering why British Columbia experienced such a mild winter and early spring, you could maybe blame it on a mysterious "blob" of warm water in the Pacific Ocean.

Tar ball deposition on Goa's beaches affecting marine life, says NIO study on Business Standard. To carry out study the NIO also collected samples from Baga, Candolim, Calungute and Mandrem beaches from North Goa and Velsao, Betalbatim, Colva and Benaulim from South Goa.

Study finds genetic evidence of climate-change adaptation.

Our results showed that local fisheries have negatively impacted the marine biodiversity of the ecosystem causing sharp declines of common dolphins and major fish stocks and weakening the robustness of the marine food web.

A concentration of pelagic sharks was observed in an area of western Queen Charlotte Sound, British Columbia, during systematic shipboard line-transect surveys conducted (2004 to 2006) for marine mammals throughout coastal waters of British Columbia. Surveys allowed only brief observations of sharks at the surface, providing limited opportunity to confirm species identity. Observers agreed, however, that salmon sharks Lamna ditropis (Lamnidae) were most common, followed by blue sharks Prionace glauca (Carcharhinidae). Both conventional and model-based distance sampling statistical methods produced large abundance estimates (similar to 20000 sharks of all species combined) concentrated within a hotspot encompassing similar to 10\% of the survey region. Neither statistical method accounted for submerged animals, thereby underestimating abundance. Sightings were made in summer, corresponding with southern movement of pregnant salmon sharks from Alaska. The previously undocumented high density of these pelagic sharks in this location has implications for understanding at-sea mortality of returning Pacific salmon Oncorhynchus spp. (Salmonidae) and for assessing conservation status of sharks in Canada and beyond. We recommend that a dedicated Canada-US sightings and biological sampling programme be considered, perhaps under the UN Transboundary Species Fishery programme.

July 23, 2007 – Over the last five years, large, predatory Humboldt squid have moved north from equatorial waters and invaded the sea off Central California, where they may be decimating populations of Pacific hake, an important commercial fish.

All persons practicing veterinary medicine in North Carolina shall report these listed diseases and conditions to the State Veterinarian's office by telephone within two hours after the disease is reasonably suspected to exist.

Phytoplankton blooms are increasingly conspicuous along the world's coastlines, and the toxic effects of these blooms have become a major concern. Nutrient enrichment often causes phytoplankton blooms, which decrease water transparency, but little is known about the effects of such light regime changes on whole communities of the continental shelf. A series of simulations designed to evaluate the potential effects of shading by phytoplankton blooms on community organization were conducted using a balanced trophic model of the West Florida Shelf ecosystem and the Ecopath with Ecosim modeling approach. Many functional groups in the system were predicted to decline as benthic primary production was inhibited through shading by phytoplankton, especially when associated biogenic habitat was lost. Groups that obtain most of their energy from planktonic pathways increased when shading impact and associated structural habitat degradation were complemented by enhanced phytoplankton production. Groups predicted to decline as the result of shading by plankton blooms include seabirds, manatees, and a variety of demersal and benthic fishes and invertebrates. Some counterintuitive predictions of declines (mackerel, seabirds, and surface pelagics) resulted because these groups are somewhat dependent on benthic primary production. The overall effect of the simulated bloom-associated shading of benthic primary producers resembled a trophic cascade where the number of full cycles of biomass gains and losses was approximately equal to the number of trophic levels in the system (4.7). (C) 2003 Elsevier B.V. All rights reserved.

Efforts to encourage Icelandic fisheries to make use of Atlantic bluefin tuna catch quotas allotted to Iceland have yet to prove fruitful. While tuna goes for high prices, specialised ships are necessary to make tuna fishing profitable. Chartering foreign boats to develop tuna fishing experience within the Icelandic fishing industry would require authorisation from the […]

More than 100 salmon trollers packed a Sitka meeting Wednesday night with sharp questions about the future of an iconic Southeast Alaska fishery, facing what could be an unprecedented full shutdown of this year’s chinook trolling season. State officials are scrambling to open the fishery after it was effectively closed by a federal judge — but damage has already been done.

A total of 80 stockfish fillets of Northeast Arctic cod (Gadus morhua), traditionally open-air-dried in northern Norway, was examined for the presence and viability of larval parasitic nematodes of the family Anisakidae. Anisakids (particularly those belonging to genera Anisakis and Pseudoterranova) are of public health and economic concern globally, since they are responsible for an underestimated fish-borne zoonotic disease called anisakidosis.

Worms infecting fish grow four times faster at higher temperatures and manipulate the behavior of fish.

Landmark report says invasive species are major threat to biodiversity and dealing with them requires global cooperation

Data cited by the B.C. Centre for Disease Control suggests 75 per cent of wild Pacific salmon are infected with the parasite. If fish is to be consumed uncooked, killing the parasites requires it to be frozen at -20 C for at least a week, Young said. Most commercial sushi-grade seafood suppliers freeze at -40 C.