Robert L. Shipp

Movement of Tagged Red Snapper in the Northern Gulf of Mexico

Abstract A tagging study of adult red snapper Lutjanus campechanus was conducted in an area of artificial reefs in the northcentral Gulf of Mexico during March 1995 through August 1999. A total of 2,932 red snapper angled at nine artificial reef tagging sites were measured and tagged with internal anchor tags. Tagged fish were either released over their site of capture or transported to another tagging site for release. Of the 561 recaptures made of 519 fish (42 multiple recaptures), 235 recaptures were made at tagging sites on subsequent tagging trips and 326 recoveries were reported by recreational and commercial fishers. Mean distance moved was 29.6 km; the farthest distance moved was 352 km. Mean time at liberty was 404 d; the longest time at liberty was 1,501 d. During the study, two strong hurricanes passed near the study area. The occurrence of hurricanes significantly affected the probability of red snapper movement, as did time at liberty, total length of fish tagged, and transportation of fish t...

A Perspective on Marine Reserves as a Fishery Management Tool

Abstract Marine protected areas (MPAs) are portions of the marine environment which are protected from some or all human activity. Where extraction of living resources is forbidden, these MPAs are best referred to as marine reserves. Often these are proposed as a safeguard against collapse of fish stocks, although reserves may have numerous other beneficial purposes. However, as a tool for fisheries management, where optimal and/or maximum sustainable yield is the objective, I submit that reserves are generally not as effective as traditional management measures, and are not appropriate for the vast majority of marine species. This is because most marine species are far too mobile to remain within a reserve and/or are not overfished. However, in the United States, of those marine fishes that are experiencing overfishing or are overfished, most have come under management within the last decade, employing more traditional fishery management measures, and are experiencing recovery. For those few species whic...

A perspective of the importance of artificial habitat on the management of red snapper in the Gulf of Mexico.

The Gulf of Mexico red snapper fishery has been declared as overfished, and overfishing is occurring. More stringent regulations, including reduced catch quotas and restrictions on the shrimp fishery to reduce bycatch of juvenile snappers, are anticipated. However, with projected rebuilding, maximum sustainable yield (MSY) is estimated to be between 11 and 25 million pounds. This exceeds previously recorded annual yields from U.S. Gulf waters. The fishery began during the mid 19th century off the northeastern Gulf coast, with harvests of only about 2 million pounds. Even at this rate, the stocks were depleted rapidly, and the fleets moved further south and east to find new sources. Numerous exploratory cruises to the western Gulf in the late 19th century found minimal snapper populations, but high concentrations discovered off Vera Cruz, Mexico, attracted fishers, and this area was the major source of snappers for more than a century. The deployment of petroleum structures in the mid 20th century in the western Gulf and thousands of artificial reefs in the north-central Gulf have markedly increased red snapper habitat in those areas. Currently, snapper populations around artificial reefs in the north-central and northwestern Gulf support the majority of the U.S. harvest. If habitat is limiting, the designations of “overfishing” and “overfished” may be misleading, and “unrealized harvest potential” may be a more accurate descriptor of the current status of the stock given the increased presence of additional habitat for red snapper. Decreases in these artificial structures (owing to natural degradation or removal) may decrease future harvest potential.

Notes: Procedure for Rapid Processing of Large Otoliths

Abstract We describe a rapid method for preparing and reading thin sections of large (>3 mm in diameter) otoliths through the use of a thin-sectioning machine that is equipped with both a cut-off saw and a calibrated precision grinder, both of which have aluminum guide arms for feeding otoliths mounted to petrographic glass slides. The procedure, which greatly reduces the time required for sectioning otoliths and polishing them for reading annuli, allows an experienced technician to quickly prepare and read otoliths without sacrificing quality and precision.

Gulf-Wide Decreases in the Size of Large Coastal Sharks Documented by Generations of Fishermen

Abstract Large sharks are top predators in most coastal and marine ecosystems throughout the world, and evidence of their reduced prominence in marine ecosystems has been a serious concern for fisheries and ecosystem management. Unfortunately, quantitative data to document the extent, timing, and consequences of changes in shark populations are scarce, thwarting examination of long-term (decadal, century) trends, and reconstructions based on incomplete data sets have been the subject of debate. Absence of quantitative descriptors of past ecological conditions is a generic problem facing many fields of science but is particularly troublesome for fisheries scientists who must develop specific targets for restoration. We were able to use quantitative measurements of shark sizes collected annually and independently of any scientific survey by thousands of recreational fishermen over the last century to document decreases in the size of large sharks from the northern Gulf of Mexico. Based on records from fishing rodeos in three U.S. coastal states, the size (weight or length) of large sharks captured by fishermen decreased by 50–70% during the 20 years after the 1980s. The pattern is largely driven by reductions in the occurrence and sizes of Tiger Sharks Galeocerdo cuvier and Bull Sharks Carcharhinus leucas and to a lesser extent Hammerheads Sphyrna spp. This decrease occurred despite increasing fishing effort and advances in technology, but it is coincident with the capitalization of the U.S. commercial shark long-line fishery in the GOM.

Venting and Reef Fish Survival: Perceptions and Participation Rates among Recreational Anglers in the Northern Gulf of Mexico

Abstract Fisheries scientists, managers, and industry have developed innovative tools and techniques to improve the survival of fishes captured and released in deepwater settings. Venting involves the insertion of a hollow needle to deflate a fishs swim bladder and is among the most widely promoted barotrauma mitigation techniques. However, its efficacy has been the subject of intense debate. In the northern Gulf of Mexico, venting tools are mandatory tackle for offshore reef anglers, but current mandates on usage are being reconsidered. We surveyed recreational and tournament anglers to understand the popularity and perceived effectiveness of venting and identify factors that affect these measures. Our survey results indicate that approximately two-thirds of anglers vent the fish they release offshore and most perceive it to be effective for improving survival rates. Among recreational anglers, we found that primary fishing locale (inshore, offshore) and experience were powerful predictors of perception...

A New Species of the Genus Echiodon (Pisces: Carapidae) from the Eastern Gulf of Mexico

Echiodon dawsoni is described from the eastern Gulf of Mexico and a key to the species of Echiodon is provided. Taxonomic analysis of the recognized species attributable to Echiodon reveals two species groups. One of these has an Old World distribution, E. dentatus of the Mediterranean and E. drummondi of the eastern North Atlantic. The second group is of New World distribution, E. exsilium of the eastern Pacific, E. dawsoni of the eastern Gulf of Mexico, and an undescribed species, presently known from but two specimens, from the western