Mitochondrial DNA markers to identify commercial spiny lobster species (Panulirus spp.) from the Pacific coast of Mexico: an application on phyllosoma larvae

Molecular markers based on mitochondrial DNA (mtDNA) are extensively used to study genetic relationships. mtDNA has been used in phylogenetic studies to understand the evolutionary history of species because it is maternally inherited and is not subject to genetic recombination (Gyllensten et al., 1991). The high mutation rate of mtDNA makes it a useful tool for differentiating between closely related species (Brown et al., 1979)—a tool that is especially important when significant variations occur between species, but not within species (Hill et al., 2001; Blair et al., 2006; Chow et al., 2006a).

Survival of white marlin (Tetrapturus albidus) released from commercial pelagic longline gear in the western North Atlantic

To estimate postrelease survival of white marlin (Tetrapturus albidus) caught incidentally in regular commercial pelagic longline fishing operations targeting swordfish and tunas, short-duration popup satellite archival tags (PSATs) were deployed on captured animals for periods of 5−43 days. Twenty (71.4%) of 28 tags transmitted data at the preprogrammed time, including one tag that separated from the fish shortly after release and was omitted from subsequent analyses. Transmitted data from 17 of 19 tags were consistent with survival of those animals for the duration of the tag deployment. Postrelease survival estimates ranged from 63.0% (assuming all nontransmitting tags were evidence of mortality) to 89.5% (excluding nontransmitting tags from the analysis). These results indicate that white marlin can survive the trauma resulting from interaction with pelagic longline gear, and indicate that current domestic and international management measures requiring the release of live white marlin from this fishery will reduce fishing mortality on the Atlantic-wide stock.

Estimates of commercial longline selectivity for Pacific halibut (Hippoglossus stenolepis) from multiple marking experiments

The term “selectivity” refers to the relationship between the size (or age) of a fish and its vulnerability to a given kind of fishing gear. A selectivity schedule, along with other parameters, is normally estimated in the course of fitting a stock assessment model, and the estimated schedule can have a large effect on both the estimate of present stock abundance and the choice of an appropriate harvest rate. The form of the relationship is usually not known and not well determined by the data, and equally good model fits can often be obtained with different plausible specifications of selectivity. Choosing among the model fits and associated abundance estimates in this situation is problematic (Sigler, 1999; Sullivan et al., 19

A list of commercial fish species from Santarem, state of Para, Brazil

A list, comprising 129 species in 23 families, is presented of the fish commonly caught in 1992/93 in the commercial fisheries around Santarem, Para State, Brazil. The most important families were the Pimelodidae (22 spp.), Cichildae (20) and Serrasalmidae (15), and six species contribute over 50% of the catch in weight.

The commercial use of chicken processing wastes to raise hybrid catfish (Clarias gariepinus) x Clarias macrocephalus) in Thailand

The article highlights the commercial use of chicken processing wastes on nursery and growout operations of hybrid catfish (Clarias gariepinus x Clarias macrocephalus) farm in Thailand.

Commercial production and marketing of Nile tilapia (Oreochromis niloticus) fry in Chonburi and Chachoengsao provinces, Thailand

Nile tilapia (Oreochromis niloticus) fry production and marketing in the provinces of Chonburi and Chachoengsao, Thailand are discussed, covering historical background, production methodology, transfer of technology to other region, and future trends.

Quantifying gregarine infestation of Penaeus vannamei on a commercial shrimp farm and some attempts at treatment

The gregarine (Nematopsis spp.) infestation in Penaeus vannamei on a commercial shrimp pond is discussed focusing on quantifying the parasites and some attempts to control infestation.

Evaluation of the carcass and commercial characteristics of carps

The role of carcass evaluation techniques in aquaculture research programs, especially in genetics, breeding, production management, feeding and nutrition, cannot be overemphasized. Knowledge of production efficiencies and growth potentials in relation to desired carcass attributes has provided an impetus to improvements in genetic selection techniques and management of aquatic food animals. Accurate, standard and uniform methods of carcass evaluation are critically important. A standard format developed for collection of data on carps is presented in this paper.

Escapement of the Cape rock lobster (Jasus lalandii ) through the mesh and entrance of commercial traps

Metal-framed traps covered with polyethylene mesh used in the fishery for the South African Cape rock lobster (Jasus lalandii) incidentally capture large numbers of undersize (<75 mm CL) specimens. Air-exposure, handling, and release procedures affect captured rock lobsters and reduce the productivity of the stock, which is heavily fished. Optimally, traps should retain legalsize rock lobsters and allow sublegal animals to escape before traps are hauled. Escapement, based on lobster morphometric measurements, through meshes of 62 mm, 75 mm, and 100 mm was investigated theoretically under controlled conditions in an aquarium, and during field trials. SELECT models were used to model escapement, wherever appropriate. Size-selectivity curves based on the logistic model fitted the aquarium and field data better than asymmetrical Richards curves. The lobster length at 50% retention (L50) on the escapement curve for 100-mm mesh in the aquarium (75.5 mm CL) approximated the minimum legal size (75 mm CL); however estimates of L50 increased to 77.4 mm in field trials where trapentrances were sealed, and to 82.2 mm where trap-entrances were open. Therfore, rock lobsters that cannot escape through the mesh of sealed field traps do so through the trap entrance of open traps. By contrast, the wider selection range and lower L25 of field, compared to aquarium, trials (SR = 8.2 mm vs. 2.6 mm; L25 =73.4 mm vs. 74.1 mm), indicate that small lobsters that should be able to escape from 100-mm mesh traps do not always do so. Escapement from 62-mm mesh traps with open entrance funnels increased by 40−60% over sealed traps. The findings of this study with a known size distribution, are related to those of a recent indirect (comparative) study for the same species, and implications for trap surveys, commercial catch rates, and ghost fishing are discussed.

The U.S. Gulf of Mexico Pink Shrimp, Farfantepenaeus duorarum, Fishery: 50 Years of Commercial Catch Statistics

U.S. Gulf of Mexico, pink shrimp, Farfantepenaeus duorarum, catch statistics have been collected by NOAA’s National Marine Fisheries Service, or its predecessor agency, for over 50 years. Recent events, including hurricanes and oil spills within the ecosystem of the fishery, have shown that documentation of these catch data is of primary importance. Fishing effort for this stock has fluctuated over the 50-year period analyzed, ranging from 3,376 to 31,900 days fished, with the most recent years on record, 2008 and 2009, exhibiting declines up to 90% relative to the high levels recorded in the mid 1990’s. Our quantification of F. duorarum landings and catch rates (CPUE) indicates catch have been below the long-term average of about 12 million lb for all of the last 10 years on record. In contrast to catch and effort, catch rates have increased in recent years, with record CPUE levels measured in 2008 and 2009, of 1,340 and 1,144 lb per day fished, respectively. Our regression results revealed catch was dependent upon fishing effort (F=98.48df=1, 48, p<0.001, r2=0.67), (Catch=1,623,378 + (520) × (effort)). High CPUE’s measured indicate stocks were not in decline prior to 2009, despite the decline in catch. The decrease in catch is attributed in large part to low effort levels caused by economical and not biological or habitat related conditions. Future stock assessments using these baseline data will provide further insights and management advice concerning the Gulf of Mexic

Classification of Coastal Communities Reporting Commercial Fish Landings in the U.S. Northeast Region: Developing and Testing a Methodology

The National Marine Fisheries Service is required by law to conduct social impact assessments of communities impacted by fishery management plans. To facilitate this process, we developed a technique for grouping communities based on common sociocultural attributes. Multivariate data reduction techniques (e.g. principal component analyses, cluster analyses) were used to classify Northeast U.S. fishing communities based on census and fisheries data. The comparisons indicate that the clusters represent real groupings that can be verified with the profiles. We then selected communities representative of different values on these multivariate dimensions for in-depth analysis. The derived clusters are then compared based on more detailed data from fishing community profiles. Ground-truthing (e.g. visiting the communities and collecting primary information) a sample of communities from three clusters (two overlapping geographically) indicates that the more remote techniques are sufficient for typing the communities for further in-depth analyses. The in-depth analyses provide additional important information which we contend is representative of all communities within the cluster.

Census of Active Commercial Fishermen in Puerto Rico: 2008

The implementation of Puerto Rican Regulation No. 6768, which overhauled the existing fishery management framework, generated considerable hostility towards local managers. Among the controversial management measures adopted in 2004 were the assignment of fishing licenses based on fishing income, the establishment of closed seasons, and new minimum size restrictions for commercially valuable species. Though tensions have subsided, considerable opposition to these regulations remains. This paper provides a characterization of the current population of active small-scale fishermen, discusses their perceptions about the biological and socio-economic condition of the fishery, and describes their attitudes towards the new management framework. This study revealed that the number of active fishermen decreased from 1,731 in 1988 to 868 in 2008. Although a declining resource base was one of the main drivers behind these waning participation statistics, rising fuel costs and burdensome regulations exacerbated the rate of attrition. The majority of the fishermen were middleaged men (50 years) with moderate levels of formal education and high levels of fishing dependence which limited their employment opportunities outside the fishery. Most of the vessels were small (20 ft) and outfitted with a single outboard engine (80 hp). Hook and line and SCUBA were dominant gears because of their versatility and cost effectiveness. Fishermen suggested that their opposition to the regulations would continue unless they were afforded greater regulatory flexibility and provided with a larger role in the decision-making process. Fishermen were adamant about the need to reconsider the income reporting requirements to secure a fishing license because of the potential for losing public assistance benefits. They also objected to increasing the minimum size of many deepwater snapper (Lutjanidae) and grouper (Serranidae) species because it forced them to discard dead fish, a practice they consider wasteful since these species do not survive the ascent to the surface once hooked.

Commercial Whaling, Especially for Gray Whales, Eschrichtius robustus, and Humpback Whales, Megaptera novaeangliae, at California and Baja California Shore Stations in the 19th Century (1854–1899)

Shore whaling along North America’s California and Baja California coasts during 1854–99 was ancillary to the offshore and alongshore American whale fishery, which had begun in the North Pacific in the early 1800’s and was flourishing by the 1840’s. From its inception at Monterey, Calif., in the mid 1850’s, the shore fishery, involving open boats deployed from land to catch and tow whales for processing, eventually spread from Monterey south to San Diego and Baja California and north to Crescent City near the California–Oregon border. It had declined to a relict industry by the 1880’s, although sporadic efforts continued into the early 20th century. The main target species were gray whales, Eschrichtius robustus, and humpback whales, Megaptera novaeangliae, with the valuable North Pacific right whale, Eubalaena japonica, also pursued opportunistically. Catch data are grossly incomplete for most stations; no logbooks were kept for these operations as they were for high-seas whaling voyages. Even when good information is available on catch levels, usually as number of whales landed or quantity of oil produced, it is rarely broken down by species. Therefore, we devised methods for extrapolation, interpolation, pro rationing, correction, and informed judgment to produce time series of catches. The resulting estimates of landings from 1854 to 1899 are 3,150 (SE = 112) gray whales and 1,637 (SE = 62) humpback whales. The numbers landed should be multiplied by 1.2 to account for hunting loss (i.e. whales harpooned or shot but not recovered and processed).

Small-scale Commercial Culturing of Northern Bay Scallops, Argopecten irradians irradians, in Atlantic United States and Canada

In recent decades, hatchery-growout culture of oysters, Crassostrea virginica, and northern quahogs, Mercenaria mercenaria, has been commercially successful in Atlantic United States and oysters in Atlantic Canada. Culturists have not had success, as yet, with northern bay scallops, Argopecten irradians irradians. Large mortalities occur during the culture process, mainly because the scallops are relatively delicate and some die when handled. In addition, too little edible meat, i.e. the adductor muscle, is produced for the culture operation to be profitable. However, three companies, one in Massachusetts, one in New Brunswick, and one on Prince Edward Island, Canada, have discovered that they can produce bay scallops successfully by harvesting them when partially-to fully-grown and selling them whole. In restaurants, the scallops are cooked and served with all their meats (adductor muscles and rims) and also with the shells, which have been genetically-bred for bright colors. The scallop seed are produced in hatcheries and then grown in lantern or pearl nets and cages to market size. Thus far, production has been relatively small, just beyond the pilot-scale, until a larger demand develops for this product.

Testing a Device to Exclude Ovigerous Blue Crabs, Callinectes sapidus, from Commercial Pots

North Carolina fishery managers are considering methods to offer greater protection to the blue crab, Callinectes sapidus, spawning stock while maintaining a viable commercial fishery for female blue crabs in high salinity estuaries. We tested how effectively wire rectangles, or excluders, of two internal sizes, 45x80 mm and 45x90 mm, would prevent entry of ovigerous female (sponge) crabs into pots relative to control pots (without excluders) while maintaining sizes and catch rates of male and nonsponged female hard crabs. Field sampling among three pot designs (two excluder sizes and control pots) was conducted in Core Sound, N.C., during 2004–06. Median sizes (carapace widths) of mature female crabs were not different among the three pot types. However, median sizes of male crabs and sponge crabs were greater in control pots than pots with either size of excluder. Catch rates of mature female crabs from control pots were greater than from pots with 45x85 mm excluders. Catch rates of legal male and sponge crabs from control pots were greater than from pots with either size of excluder. Results indicate that using excluders involves a tradeoff between reducing catches and sizes of sponge crabs while also reducing sizes and catches of legally harvestable nonsponge crabs; moreover, the reduction in total catch and sizes would be greater for legal male crabs than for legal nonsponged female crabs. In high salinity waters close to North Carolina’s existing no-harvest blue crab sanctuaries, where females typically dominate catches of hard crabs, the benefit of using excluders to prevent entry of sponge crabs may outweigh a potentially modest decrease in landings of nonsponged females.