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

Humpback and Fin Whaling in the Gulf of Maine from 1800 to 1918

The history of whaling in the Gulf of Maine was reviewed primarily to estimate removals of humpback whales, Megaptera novaeangliae, especially during the 19th century. In the decades from 1800 to 1860, whaling effort consisted of a few localized, small-scale, shore-based enterprises on the coast of Maine and Cape Cod, Mass. Provincetown and Nantucket schooners occasionally conducted short cruises for humpback whales in New England waters. With the development of bomb-lance technology at mid century, the ease of killing humpback whales and fin whales, Balaenoptera physalus, increased. As a result, by the 1870’s there was considerable local interest in hunting rorquals (baleen whales in the family Balaenopteridae, which include the humpback and fin whales) in the Gulf of Maine. A few schooners were specially outfitted to take rorquals in the late 1870’s and 1880’s although their combined annual take was probably no more than a few tens of whales. Also in about 1880, fishing steamers began to be used to hunt whales in the Gulf of Maine. This steamer fishery grew to include about five vessels regularly engaged in whaling by the mid 1880’s but dwindled to only one vessel by the end of the decade. Fin whales constituted at least half of the catch, which exceeded 100 animals in some years. In the late 1880’s and thereafter, few whales were taken by whaling vessels in the Gulf of Maine.

Age, size, and sexual maturity of channeled whelk (Busycotypus canaliculatus) in Buzzards Bay, Massachusetts

With the southern New England lobster fishery in distress, lobster fishermen have focused more effort toward harvesting channeled whelk (Busycotypus canaliculatus). However, minimal research has been conducted on the life history and growth rates of channeled whelk. Melongenid whelks generally grow slowly and mature late in life, a characteristic that can make them vulnerable to overfishing as fishing pressure increases. We sampled channeled whelk from Buzzards Bay, Massachusetts, in August 2010 and in July 2011, studied their gonad development by histology, and aged them by examining opercula. Males had a slower growth rate and a lower maximum size than females. Male whelk reached 50% maturity (SM50) at 115.5 mm shell length (SL) and at the age of 6.9 years. Female whelk reached SM50 at 155.3 mm SL and at the age of 8.6 years. With a minimum size limit of 69.9 mm (2.75 in) in shell width, males entered the fishery at 7.5 years, a few months after SM50, but females entered the fishery at 6.3 years, approximately 2 years before SM50. Increased fishing pressure combined with slow growth rates and the inability to reproduce before being harvested can easily constrain the long-term viability of the channeled whelk fishery in Massachusetts.

Age and growth of the swordfish (Xiphias gladius L.) in the waters around Taiwan determined from anal-fin rays

Age and growth of the swordfish (Xiphias gladius) in Taiwan waters was studied from counts of growth bands on cross sections of the second ray of the first anal fin. Data on lower jaw fork length and weight, and samples of the anal fin of male and female swordfish were collected from three offshore and coastal tuna longline fishing ports on a monthly basis between September 1997 and March 1999. In total, 685 anal fins were collected and 627 of them (293 males and 334 females) were aged successfully. The lower jaw fork lengths of the aged individuals ranged from 83.4 to 246.6 cm for the females and from 83.3 to 206 cm for the males. The radii of the fin rays and growth bands on the cross sections were measured under a dissecting microscope equipped with an image analysis system. Trends in the monthly marginal increment ratio indicated that growth bands formed once a year. Thus, the age of each fish was deter-mined from the number of visible growth bands. Two methods were used to estimate and compare the standard and the generalized von Bertalanffy growth parameters for both males and females. The nonlinear least square estimates of the generalized von Bertalanffy growth parameters in method II, in which a power function was used to describe the relationship between ray radius and LJFL, were recommended as most acceptable. There were significant differences in growth parameters between males and females. The growth parameters estimated for females were the following: asymptotic length (L∞) = 300.66 cm, growth coefficient (K) = 0.040/yr, age at zero length (t0) = –0.75 yr, and the fitted fourth parameter (m) = –0.785. The growth parameters estimated for males were the following: asymptotic length (L∞) = 213.05 cm, growth coefficient (K) = 0.086/yr, age at zero length (t0) = –0.626 yr, and the fitted fourth parameter (m) = –0.768.

Anchorage of air bladder with the interspinous bone of the anal fin in Lactarius lactarius (Bloch and Schneider, 1801)

Specimens of the false trevally (Lactarius lactarius ), 127 to 221 mm in total length, were studied for the mode of anchorage of the air-bladder with the interspinous bone of the anal fin. The 1st and 2nd interspinous bones are fused together into a single piece (named here as the anchor bone) which pierces through the air-bladder, dividing it into two intercommunicating chambers at its upper end, and ultimately articulates with the 10th vertebral bone. The lower end of the bone is broad, fan like with one side affording articulation with the 1st and 2nd anal spines. This is an unique feature of great taxonomical importance to L. lactarius, the only species in the family Lactariidae. The anal fin counts (23-27) and vertebral counts (23) are also given.