Assessment of Lutjanus vivanus and Lutjanus buccanella in the north Caribbean coast of Costa Rica

This paper presents results of stock assessment on two snapper species, Lutjanus vivanus and L. buccanella, in the north Caribbean coast of Costa Rica. Growth parameters, mortality rates, length-weight relationships, recruitment patterns and exploitation rates for the two species are given. Results indicate that the two species are subject to relatively low exploitation levels with E = 0.25 for L. vivanus and E = 0.39 for L. buccanella.

Mitochondrial gene sequences useful for species identification of western North Atlantic Ocean sharks

Molecular-based approaches for shark species identification have been driven largely by issues specific to the fishery. In an effort to establish a more comprehensive identification data set, we investigated DNA sequence variation of a 1.4-kb region from the mitochondrial genome covering partial sequences from the 12S rDNA, 16S rDNA, and the complete valine tRNA from 35 shark species from the Atlantic fishery. Generally, within-species variability was low in relation to interspecific divergence because species haloptypes formed monophyletic groups. Phylogenetic analyses resolved ordinal relationships among Carcharhiniformes and Lamniformes, and revealed support for the families Sphyrnidae and Triakidae (within Carcharhiniformes) and Lamnidae and Alopidae (within Lamniformes). The combination of limited intraspecific variability and sufficient between-species divergence indicates that this locus is suitable for species identification.

Application of pop-up satellite archival tag technology to estimate postrelease survival of white marlin (Tetrapturus albidus) caught on circle and straight-shank (“J”) hooks in the western North Atlantic recreational fis

Short-duration (5- or 10-day) deployments of pop-up satellite archival tags were used to estimate survival of white marlin (Tetrapturus albidus) released from the western North Atlantic recreational fishery. Forty-one tags, each recording temperature, pressure, and light level readings approximately every two minutes for 5-day tags (n= 5) or four minutes for 10-day tags (n= 36), were attached to white marlin caught with dead baits rigged on straight-shank (“J”) hooks (n =21) or circle hooks (n=20) in offshore waters of the U.S. Mid-Atlantic region, the Dominican Republic, Mexico, and Venezuela. Forty tags (97.8%) transmitted data to the satellites of the Argos system, and 33 tags (82.5%) transmitted data consistent with survival of tagged animals over the deployment duration. Approximately 61% (range: 19−95%) of all archived data were successfully recovered from each tag. Survival was significantly (P<0.01) higher for white marlin caught on circle hooks (100%) than for those caught on straight-shank (“J”) hooks (65%). Time-to-death ranged from 10 minutes to 64 hours following release for the seven documented mortalities, and five animals died within the first six hours after release. These results indicate that a simple change in hook type can significantly increase the survival of white marlin released from recreational fis

Diet of oceanic loggerhead sea turtles (Caretta caretta) in the central North Pacific

Diet analysis of 52 loggerhead sea turtles (Caretta caretta) collected as bycatch from 1990 to 1992 in the high-seas driftnet fishery operating between lat. 29.5°N and 43°N and between long. 150°E and 154°W demonstrated that these turtles fed predominately at the surface; few deeper water prey items were present in their stomachs. The turtles ranged in size from 13.5 to 74.0 cm curved carapace length. Whole turtles (n =10) and excised stomachs (n= 42) were frozen and transported to a laboratory for analysis of major faunal components. Neustonic species accounted for four of the five most common prey taxa. The most common prey items were Janthina spp. (Gastropoda); Carinaria cithara Benson 1835 (Heteropoda); a chondrophore, Velella velella (Hydrodia); Lepas spp. (Cirripedia), Planes spp. (Decapoda: Grapsidae), and pyrosomas (Pyrosoma spp.).

Ecosystem-based Management for Protected Species in the North Pacific Fisheries

In the North Pacific Ocean, an ecosystem-based fishery management approach has been adopted. A significant objective of this approach is to reduce interactions between fishery-related activities and protected species. We review management measures developed by the North Pacific Fishery Management Council and the National Marine Fisheries Service to reduce effects of the groundfish fisheries off Alaska on marine mammals and seabirds, while continuing to provide economic opportunities for fishery participants. Direct measures have been taken to mitigate known fishery impacts, and precautionary measures have been taken for species with potential (but no documented) interactions with the groundfish fisheries. Area closures limit disturbance to marine mammals at rookeries and haulouts, protect sensitive benthic habitat, and reduce potential competition for prey resources. Temporal and spatial dispersion of catches reduce the localized impact of fishery removals. Seabird avoidance measures have been implemented through collaboration with fishery participants and have been highly successful in reducing seabird bycatch. Finally, a comprehensive observer monitoring program provides data on the location and extent of bycatch of marine mammals and seabirds. These measures provide managers with the flexibility to adapt to changes in the status of protected species and evolving conditions in the fisheries. This review should be useful to fishery managers as an example of an ecosystem-based approach to protected species management that is adaptive and accounts for multiple objectives.

Historical Catches of Humpback Whales, Megaptera novaeangliae, in the North Atlantic Ocean: Estimates of Landings and Removals

Whaling for humpback whales, Megaptera novaeangliae, in the North At- lantic Ocean has occurred in various forms (e.g. for local subsistence, for oil to be sold commercially, using hand harpoons and deck-mounted cannons, using oar-driven open boats and modern powered catcher boats) from the early 1600’s to the present. Several previous attempts to estimate the total numbers of humpback whales removed were considered close to comprehensive, but some uncertainties remained. Moreover, the statistical uncertainty was not consistently presented with the previous estimates. Therefore, we have pursued several avenues of additional data collection and conducted further analyses to close outstanding data gaps and address remaining issues. Our new estimates of landings and total removals of humpback whales from the North Atlantic are 21,476 (SE=214) and 30,842 (SE=655), respectively. These results include statistical uncertainty, reflect new data and improved analysis methods, and take account of some fisheries for which estimates had not been made previously. The new estimates are not sufficiently different from previous ones to resolve the major inconsistencies and discrepancies encountered in efforts to determine the conservation status of humpback whale populations in the North Atlantic.

Nineteenth-century Ship-based Catches of Gray Whales, Eschrichtius robustus, in the Eastern North Pacific

The 19th century commercial ship-based fishery for gray whales, Eschrichtius robustus, in the eastern North Pacific began in 1846 and continued until the mid 1870’s in southern areas and the 1880’s in the north. Henderson identified three periods in the southern part of the fishery: Initial, 1846–1854; Bonanza, 1855–1865; and Declining, 1866–1874. The largest catches were made by “lagoon whaling” in or immediately outside the whale population’s main wintering areas in Mexico—Magdalena Bay, Scammon’s Lagoon, and San Ignacio Lagoon. Large catches were also made by “coastal” or “alongshore” whaling where the whalers attacked animals as they migrated along the coast. Gray whales were also hunted to a limited extent on their feeding grounds in the Bering and Chukchi Seas in summer. Using all available sources, we identified 657 visits by whaling vessels to the Mexican whaling grounds during the gray whale breeding and calving seasons between 1846 and 1874. We then estimated the total number of such visits in which the whalers engaged in gray whaling. We also read logbooks from a sample of known visits to estimate catch per visit and the rate at which struck animals were lost. This resulted in an overall estimate of 5,269 gray whales (SE = 223.4) landed by the ship-based fleet (including both American and foreign vessels) in the Mexican whaling grounds from 1846 to 1874. Our “best” estimate of the number of gray whales removed from the eastern North Pacific (i.e. catch plus hunting loss) lies somewhere between 6,124 and 8,021, depending on assumptions about survival of struck-but-lost whales. Our estimates can be compared to those by Henderson (1984), who estimated that 5,542–5,507 gray whales were secured and processed by ship-based whalers between 1846 and 1874; Scammon (1874), who believed the total kill over the same period (of eastern gray whales by all whalers in all areas) did not exceed 10,800; and Best (1987), who estimated the total landed catch of gray whales (eastern and western) by American ship-based whalers at 2,665 or 3,013 (method-dependent) from 1850 to 1879. Our new estimates are not high enough to resolve apparent inconsistencies between the catch history and estimates of historical abundance based on genetic variability. We suggest several lines of further research that may help resolve these inconsistencies.

History of the Bay Scallop, Argopecten irradians, Fisheries and Habitats in eastern North America, Massachusetts through northeastern Mexico

This is a broad historical overview of the bay scallop, Argopecten irradians, fishery on the East and Gulf Coasts of North America (Fig. 1). For a little over a century, from about the mid 1870’s to the mid 1980’s, bay scallops supported large commercial fisheries mainly in the U.S. states of Massachusetts, New York, and North Carolina and on smaller scales in the states in between and in western Florida. In these states, the annual harvests and dollar value of bay scallops were far smaller than those of the other important commercial mollusks, the eastern oysters, Crassostrea virginica, and northern quahogs, Mercenaria mercenaria, but they were higher than those of softshell clams, Mya arenaria (Table 1). The fishery had considerable economic importance in the states’ coastal towns, because bay scallops are a high-value product and the fishery was active during the winter months when the economies in most towns were otherwise slow. The scallops also had cultural importance as a special food, an ornament owing to its pretty shell design, and an interesting biological component of

Length-weight Relationships of Dolphinfish, Coryphaena hippurus, and Wahoo, Acanthocybium solandri: Seasonal Effects of Spawning and Possible Migration in the Central North Pacific

Weight-on-length (W-L) relationships for 2,482 dolphinfish, Coryphaena hippurus, and 1,161 wahoo, Acanthocybium solandri, were examined. Data on fork length, whole (round) weight, and sex were collected for dolphinfish at the Honolulu fish auction from March 1988 through November 1989. Unsexed weight and length data for wahoo were collected at the auction from July 1988 through November 1989. We also used sex specific weight and length data of 171 wahoo collected during 1977–1985 research cruises for analysis. Coefficients of W-L regressions were significantly different between the sexes for dolphinfish. Coefficients did not significantly differ between the sexes for wahoo based on research cruise data. In a general linear model evaluating month as a categorical factor, month was significant for female dolphinfish, male dolphinfish, and wahoo with sexes pooled. W-L and length-on-weight (L-W) relationships were fitted by nonlinear regression for all dolphinfish, female dolphinfish, male dolphinfish, and all wahoo sexes pooled. W-L relationships for monthly samples of female dolphinfish, male dolphinfish, and all wahoo with sexes pooled were also fitted by nonlinear regression. Predicted mean weight at length for wahoo was highest at the beginning of the spawning season in June and lowest after the spawning season in September. Maximum and minimum predicted mean weight at length for both sexes of dolphinfish did not correspond with the peak spawning period (March–May). Plausible migration models in conjunction with reproductive behavior were examined to explain the variability in monthly predicted mean weight at length for dolphinfish.

A Test of Computer-assisted Matching Using the North Pacific Humpback Whale, Megaptera novaeangliae, Tail Flukes Photograph Collection

Testing was conducted of a computer-assisted system for matching humpback whale tail flukes photographs. Trials with a 12,000-photographs database found no differences in match success between matching by computer and matching by comparing smaller catalogs ranging in size from 200 to 400 photographs. Tests with a 24,000-photographs database showed that, on average, the first match was found after examining about 130 photographs whether the photograph quality was excellent, good, or poor. Match success did not appear to be strongly related to whether the tail flukes had especially distinctive markings or pigment patterns (recognition quality). An advantage of computer-assisted matching is the ability to compare new photographs to the entire North Pacific collection, where no bias is introduced based on expectation of resightings within or between specific areas, or based on expectation of behavioral role (e.g. matching “known” females to “known” females).

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.

The Ragfish, Icosteus aenigmaticus Lockington, 1880: A Synthesis of Historical and Recent Records From the North Pacific Ocean and the Bering Sea

Knowledge of the distribution and biology of the ragfish, Icosteus aenigmaticus, an aberrant deepwater perciform of the North Pacific Ocean, has increased slowly since the first description of the species in the 1880’s which was based on specimens retrieved from a fish monger’s table in San Francisco, Calif. As a historically rare, and subjectively unattractive appearing noncommercial species, ichthyologists have only studied ragfish from specimens caught and donated by fishermen or by the general public. Since 1958, I have accumulated catch records of >825 ragfish. Specimens were primarily from commercial fishermen and research personnel trawling for bottom and demersal species on the continental shelves of the eastern North Pacific Ocean, Gulf of Alaska, Bering Sea, and the western Pacific Ocean, as well as from gillnet fisheries for Pacific salmon, Oncorhynchus spp., in the north central Pacific Ocean. Available records came from four separate sources: 1) historical data based primarily on published and unpublished literature (1876–1990), 2) ragfish delivered fresh to Humboldt State University or records available from the California Department of Fish and Game of ragfish caught in northern California and southern Oregon bottom trawl fisheries (1950–99), 3) incidental catches of ragfish observed and recorded by scientific observers of the commercial fisheries of the eastern Pacific Ocean and catches in National Marine Fisheries Service trawl surveys studying these fisheries from 1976 to 1999, and 4) Japanese government research on nearshore fisheries of the northwestern Pacific Ocean (1950–99). Limited data on individual ragfish allowed mainly qualitative analysis, although some quantitative analysis could be made with ragfish data from northern California and southern Oregon. This paper includes a history of taxonomic and common names of the ragfish, types of fishing gear and other techniques recovering ragfish, a chronology of range extensions into the North Pacific and Bering Sea, reproductive biology of ragfish caught by trawl fisheries off northern California and southern Oregon, and topics dealing with early, juvenile, and adult life history, including age and growth, food habits, and ecology. Recommendations for future study are proposed, especially on the life history of juvenile ragfish (5–30 cm FL) which remains enigmatic.

The Ancillary Harvest of Atlantic Menhaden, Brevoortia tyrannus, Roe on the North Carolina Coast

Gravid Atlantic menhaden, Brevoortia tyrannus, are available along the central coast of North Carolina during the fall and are harvested by the purse-seine fleet from the port of Beaufort. Virtually all of the catch, sexually immature fish included, is reduces to fish meal, fish oil, and fish solubles; however, minor quantities of roe from ripening female menhaden are extracted for local consupmtion. Routine and selective port sampling information was used to characterize the seasonal and biostatistical nautre of the roe menhaden catches at Beaufort. Fishermen recognize two size classes of roe Atlantic menhaden: "forerunners," which are usually the smallest and earliest adult menhaden encountered in the Fall Fishery, and "mammy shad," which are the largest menhaden harvested and produce the greatest roe yields. Roe is extracted from femal fish at various points along the reduction process stream and by several techniques. Vessel cremen and factory personnel extract menhaden roe for personal and local consumption. Undetermined quantities of menhaden roe are channeled into local retail seafood markets. Wholesale prices are about $20 per gallon of roe, while retail prices are about $5 per pound. Carteret County, North Carolina, is probably the only area on the U.S. Atlantic and Gulf coasts where menhaden roe is sold in retail seafood markets. The potential of extracting menhaden roe for foreign markets is discussed