The use of multibeam sonar mapping techniques to refine population estimates of the endangered white abalone (Haliotis sorenseni)

Multibeam sonar mapping techniques provide detailed benthic habitat information that can be combined with the data on species-specific habitat preferences to provide highly accurate calculations of populations in a particular area. The amount of suitable habitat available for the endangered white abalone (Haliotis sorenseni) was quantified to aid in obtaining an accurate estimate of the number of remaining individuals at two offshore banks and one island site off the coast of southern California. Habitat was mapped by using multibeam sonar survey techniques and categorized by using rugosity and topographic position analysis. Abalone densities were evaluated by using a remotely operated vehicle and video transect methods. The total amount of suitable habitat at these three sites was far greater than that previously estimated. Therefore, although present estimates of white abalone densities are several orders of magnitude lower than historic estimates, the total population is likely larger than previously reported because of the additional amount of habitat surveyed in this study.

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.

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

Microbial community analysis of Acropora palamata mucus swabs, water and sediment samples from Hawksnest Bay, St. John, U.S. Virgin Islands

Colonies of the scleractinian coral Acropora palmata, listed as threatened under the US Endangered Species Act in 2006, have been monitored in Hawksnest Bay, within Virgin Islands National Park, St. John, from 2004 through 2010 by scientists with the US Geological Survey, National Park Service, and the University of the Virgin Islands. The focus has been on documenting the prevalence of disease, including white band, white pox (also called patchy necrosis and white patches), and unidentified diseases (Rogers et al., 2008; Muller et al., 2008). In an effort to learn more about the pathologies that might be involved with the diseases that were observed, samples were collected from apparently healthy and diseased colonies in July 2009 for analysis. Two different microbial assays were performed on Epicentre Biotechnologies DNA swabs containing A. palmata coral mucus, and on water and sediment samples collected in Hawksnest Bay. Both assays are based on polymerase chain reaction (PCR) amplification of portions of the small rRNA gene (16S). The objectives were to determine 1) if known coral bacterial pathogens Serratia marcescens (Acroporid Serratiosis), Vibrio coralliilyticus (temperature-dependent bleaching, White Syndrome), Vibrio shiloi (bleaching, necrosis), and Aurantimonas coralicida (White Plague Type II) were present in any samples, and 2) if there were any differences in microbial community profiles of each healthy, unaffected or diseased coral mucus swab. In addition to coral mucus, water and sediment samples were included to show ambient microbial populations. In the first test, PCR was used to separately amplify the unique and diagnostic region of the 16S rRNA gene for each of the coral pathogens being screened. Each pathogen test was designed so that an amplified DNA fragment could be seen only if the specific pathogen was present in a sample. A positive result was indicated by bands of DNA of the appropriate size on an agarose gel, which separates DNA fragments based on the size of the molecule. DNA from pure cultures of each of the pathogens was used as a positive control for each assay.

Effects of shear on eggs and larvae of striped bass, morone saxatilis, and white perch, M. americana

Shear stress, generated by water movement, can kill fish eggs and larvae by causing rotation or deformation. Through the use of an experimental apparatus, a series of shear (as dynes/cm2)-mortality equations for fixed time exposures were generated for striped bass and white perch eggs and larvae. Exposure of striped bass eggs to a shear level of 350 dynes/cm2 kills 36% of the eggs in 1 min; 69% in 2 min, and 88% in 4 min; exposure of larvae to 350 dynes/cm2 kills 9.3% in 1 min, 30.0% in 2 min, and 68.1% in 4 min. A shear level of 350 dynes/cm2 kills 38% of the white perch eggs in 1 min, 41% in 2 min, 89% in 5 min, 96% in 10 min, and 98% in 20 min. A shear level of 350 dynes/cm2 applied to white perch larvae destroys 38% of the larvae in 1 min, 52% in 2 min, and 75% in 4 min. Results are experimentally used in conjunction with the determination of shear levels in the Chesapeake and Delaware Canal and ship movement for the estimation of fish egg and larval mortalities in the field.

Bowhead and white whale migration, distribution, and abundance in the Bering, Chukchi, and Beaufort Seas, 1975-78

From September 1975 to September 1977 we conducted field research on bowhead, Balaena mysticetus, and white, Delphinapterus leucas, whales in the U.S. Bering, Chukchi, and Beaufort Seas. The objectives were to determine the general distribution and migration of these whales in spring and autumn and to estimate abundance. We also surveyed the literature beginning in June 1975 through March 1978 to augment our empirical results. (PDF contains 48 pages)

Population assessment of two stocks of white grunt, Haemulon plumieri, from the southeastern coast of the United States

Changes in the age structure and population size of white grunt, Haemulon plumieri, from North Carolina through the Florida Keys were examined using records of landings and size frequencies of fish from commercial, re~reational, and headboat fisheries from 1986-1998. Data were stratified into two geographical areas: North Carolina and South Carolina; and southeast Florida. Population size in numbers at age was estimated for each year and geographical area by applying an uncalibrated separable virtual population analysis (SVPA) to the landings in numbers at age. A calibrated virtual population analysis, FADAPT, was also run for data from North Carolina and South Carolina. SVPA and FADAPT were used to estimate annual, age-specific fishing mortality (F) for four levels of natural mortality (M = 0.20, 0.25, 0.30, and 0.35). The best estimate of M for white grunt is 0.30. Landings of white grunt in the Carolinas for the three fisheries have generally decreased in recent years, but have held fairly steady for the species in southeast Florida. Age at entry and age at full recruitment were age-1 and age-4 for the Carolinas, and age-l and age-3 for southeast Florida. With M = 0.30, levels of fishing mortality (F) on the fully-recruited ages were 0.23 for the Carolinas and 0.33 for southeast Florida. Spawning potential ratio (SPR) at M = 0.30 was 57% for the Carolinas and 61% for southeast Florida, which indicates that the species, by definition, has not been over-exploited by fishing. The results of this assessment of the white grunt population off the Carolinas agree with the recent F/FMSY analysis of white grunt (Anonymous, 1999). (PDF contaons 72 pages)

An environmental assessment of the John Pennekamp Coral Reef State Park and the Key Largo Coral Reef Marine Sanctuary (Unpublished 1983 Report)

The Pennekamp Coral Reef State Park was established in 1960 and the Key Largo National Marine Sanctuary in 1975. Field studies, funded by NOAA, were conducted in 1980 - 1981 to determine the state of the coral reefs and surrounding areas in relation to changing environmental conditions and resource management that had occurred over the intervening years. Ten reef sites within the Sanctuary and seven shallow grass and hardbottom sites within the Park were chosen for qualitative and quantitative studies. At each site, three parallel transects not less than 400 m long were run perpendicular to the reef or shore, each 300 m apart. Observations, data collecting and sampling were done by two teams of divers. Approximately 75 percent of the bottom within the 18-m isobath was covered by marine grasses, predominantly turtle grass. The general health of the seagrasses appeared good but a few areas showed signs of stress. The inner hardbottom of the Park was studied at the two entrances to Largo Sound. Though at the time of the study the North Channel hardbottom was subjected to only moderate boat traffic, marked changes had taken place over the past years, the most obvious of which was the loss of the extensive beds of Sargassum weed, one of the most extensive beds of this alga in the Keys. Only at this site was the green alga Enteromorpha encountered. This alga, often considered a pollution indicator, may denote the effects of shore run off. The hardbottom at South Channel and the surrounding grass beds showed signs of stress. This area bears the heaviest boat traffic within the Park waters causing continuous turbidity from boat wakes with resulting siltation. The offshore hardbottom and rubble areas in the Sanctuary appeared to be in good health and showed no visible indications of deterioration. Damage by boat groundings and anchors was negligible in the areas surveyed. The outer reefs in general appear to be healthy. Corals have a surprising resiliency to detrimental factors and, when conditions again become favorable, recover quickly from even severe damage. It is, therefore, a cause for concern that Grecian Rocks, which sits somewhat inshore of the outer reef line, has yet to recover from die-off in 1978. The slow recovery, if occurring, may be due to the lower quality of the inshore waters. The patch reefs, more adapted to inshore waters, do not show obvious stress signs, at least those surveyed in this study. It is apparent that water quality was changing in the keys. Water clarity over much of the reef tract was observed to be much reduced from former years and undoubtedly plays an important part in the stresses seen today over the Sanctuary and Park. (PDF contains 119 pages)

Cruise Report 59S6-Barracuda-White Seabass

(PDF contains 3 pages.)

Cruise Report 59S3-Barracuda-White Seabass

(PDF contains 4 pages.)

The Crappies

The names: bachelor, campbellite, white bass, camp lighter, sac-a-lait, silver crappie, speckled bass, tinmouth, bar fish, Oswego bass, razorback, grassback, shiner, john demon, calico bass, strawberry bass and "crap'pee," along with 10-20 others, all refer to two rather than one species of fish. Most Maryland fishermen when applying these time honored names do not realize they are referring to two distinct species of fish. These species are the black crappie, Pornoxis nigromaculatus, and the white crappie, Pornoxis annulars. Contrary to common belief, the white crappie does not change into a black crappie during parts of the year nor are these two fish just color phases of one species. Crappies are members of the freshwater sunfish family of fishes, Centrarchidae. (PDF contains 4 pages)

Southeast White Oak River shellfish restoration project

The 42-mile-long White Oak River is one of the last relatively unblemished watery jewels of the N.C. coast. The predominantly black water river meanders through Jones, Carteret and Onslow counties along the central N.C. coast, gradually widening as it flows past Swansboro and into the Atlantic Ocean. It drains almost 12,000 acres of estuaries -- saltwater marshes lined with cordgrass, narrow and impenetrable hardwood swamps and rare stands of red cedar that are flooded with wind tides. The lower portion of the river was so renowned for fat oysters and clams that in times past competing watermen came to blows over its bounty at places that now bear names like Battleground Rock. The lower river is also a designated primary nursery area for such commercially important species as shrimp, spot, Atlantic croaker, blue crabs, weakfish and southern flounder. But the river has been discovered. The permanent population along the lower White Oak increased by almost a third since 1990, and the amount of developed land increased 82 percent during the same period. With the growth have come bacteria. Since the late 1990s, much of the lower White Oak has been added to North Carolina’s list of impaired waters because of bacterial pollution. Forty-two percent of the rivers’ oyster and clam beds are permanently closed to shellfishing because of high bacteria levels. Fully two-thirds of the river’s shellfish beds are now permanently off limits or close temporarily after a moderate rain. State monitoring indicates that increased runoff from urbanization is the probable cause of the bacterial pollution. (PDF contains 4 pages)

An assessment of post-plague reintroduced native white-clawed crayfish, a Ustropotamobius pallipes, in the Sherston Avon and Tetbury Avon, Wiltshire

This article reports on the success of reintroducing native crayfish (Austropotamobius pallipes) in the Sherston and Tetbury Avon, following extinction of the population from crayfish plague. The authors describe and review the survey methods that were used and identify a survey technique that was found to be the most rapid and robust for monitoring crayfish populations. Such a survey technique could be adopted as a standard method.

Effects of suspended sediments on the development of eggs and larvae of striped bass and white perch

The possible ecological effects of suspended sediments are manifold. Briefly, suspended sediments may cause an increased surface for microorganism growth, fewer temperature fluctuations, chemical adsorption or absorption, blanketing, mechanical-abrasive actions, and light penetration reduction (Cairns, 1968). Sherk and Cronin (1970) have pointed out that the above effects have been little studied in the estuarine environment. The ecological effects of suspended sediments on fish eggs and larvae may be of prime importance t o the C and D Canal area, an important spawning and primary nursery area for a variety of estuary: e species (Johnson,1972). This section discusses the effects of suspended sediment on the eggs and larvae of striped bass and white perch.