Some aspects of the ecology of the leatherback turtle Dermochelys coriacea at Laguna Jalova, Costa Rica

The ecology and reproductive biology of the leatherback turtle (Dennochelys coriacea) was studied on a high-energy nesting beach near Laguna Jalova, Costa Rica, between 28 March and 8 June 1985. The peak of nesting was between 15 April and 21 May. Leatherbacks here measured an average 146.6 cm straightline standard carapace length and laid an average 81.57 eggs. The eggs measured a mean 52.12 mm diameter and weighed an average of 85.01 g. Significant positive relationships were found between the carapace lengths of nesters and their clutch sizes and average diameter and weight of eggs. The total clutch weighed between 4.02 and 13.39 kg, and yolkless eggs accounted for an average 12.4% of this weight. The majority of nesters dug shallow (<24 cm) body pits and spent an average 81 minutes at the nest site. A significant number of c1utcbes were laid below the berm crest. In a hatchery 42.2% of the eggs hatched, while in natural nests 70.2% hatched. The average hatchling carapace length was 59.8 mm and weight was 44.6 g. The longevity of leatherback tracks and nests on the beach was affected by weather. One nester was recaptured about one year later off the coast of Mississippi, U.S.A. Egg poaching was intense on some sections of the Costa Rican coast. Four aerial surveys in four different months provided the basis for comparing density of nesting on seven sectors of the Caribbean coast of Costa Rica. The beach at Jalova is heavily used by green turtles (Chelonia mydJJs) after the leatherback nesting season. The role of the Parque Nacional Tortuguero in conserving the leatherback and green turtle is discussed.(PDF file contains 20 pages.)

Ecology of east Florida sea turtles: Proceedings of the Cape Canaveral, Florida Sea Turtle Workshop Miami, Florida February 26-27, 1985

The Cape Canaveral, Florida, marine ecosystem is unique. There are complex current and temperature regimes that form a faunal transition zone between Atlantic tropical and subtropical waters. This zone is rich faunistically and supports large commercial fISheries for fish, scallops, and shrimp. Canaveral is also unique because it has large numbers of sea turtles year-round, this turtle aggregation exhibiting patterned seasonal changes in numbers, size frequency, and sex ratio. Additionally, a significant portion of this turtle aggregation hibernates in the Canaveral ship channel, a phenomenon rare in marine turtle populations. The Cape Canaveral area has the largest year-round concentration of sea turtles in the United States. However, the ship channel is periodically dredged by the U.S. Army Corps of Engineers in order to keep Port Canaveral open to U.S. Navy vessels, and preliminary surveys showed that many sea turtles were incidentally killed during dredging operations. In order for the Corps of Engineers to fulfill its defense dredging responsibilities, and comply with the Endangered Species Act of 1973, an interagency Sea Turtle Task Force was formed to investigate methods of reducing turtle mortalities. This Task Force promptly implemented a sea turtle research plan to determine seasonal abundance, movement patterns, sex ratios, size frequencies, and other biological parameters necessary to help mitigate dredging conflicts in the channel. The Cape Canaveral Sea Turtle Workshop is a cooperative effort to comprehensively present research results of these important studies. I gratefully acknowledge the support of everyone involved in this Workshop, particularly the anonymous team of referees who painstakingly reviewed the manuscripts. The cover illustration was drawn by Jack C. Javech. (PDF file contains 86 pages.)

Status, biology, and ecology of fur seals: Proceedings of an International Symposium and Workshop Cambridge, England, 23-27 April 1984

The 1984 International Symposium and Workshop on the Biology of Fur Seals originated in informal talks in 1981. However, the scope and focus of the symposium remained unclear until an informal workshop was held in San Diego in June 1983. This meeting synthesised data on the foraging and pup attendance activities of six species of fur seals, and attempted to formulate a coherent framework for the adaptations associated with their maternal strategies (Gentry et al. 1986). During the workshop it was clear that comparative data on many key aspects of fur seal biology and ecology were missing. This absence of data applied not only to less well known species, for some of which considerable unpublished data existed, but also to better known species for which research in some areas had either been neglected or unreported. The value of applying the comparative method to seals, especially comparisons integrating physiology, ecology, and reproductive biology, was amply demonstrated by the results of the 1983 workshop (Gentry and Kooyman 1986). However, we were also aware that many other problems outside the area of maternal strategies could benefit from comparative data, such as recovery of populations from the effects of harvesting. Therefore, to accommodate the range of potential research, we organized this symposium to produce an up-to-date synthesis of relevant information for all species of fur seals. It was also clear that fur seal research could benefit from increased communication and collaboration among its practitioners. To foster the spread of ideas, we held oral presentations on some topics of current research and techniques and organized workshops on specific topics, in addition to providing opportunities for informal talks among participants. Thanks to generous support from the British Antarctic Survey, the National Marine Fisheries Service of the United States, and the Scientific Committee on Antarctic Research, the International Fur Seal Symposium was held at the British Antarctic Survey, Cambridge, England, 23-27 April 1984. The 36 participants are shown in Figure 1. A list of Symposium participants and authors is presented in Appendix 1 of the Proceedings. (PDF file contains 220 pages.)

Effects of temperature on the biology of the northern shrimp, Pandalus borealis, in the Gulf of Maine

Length-frequency data collected from inshore and offshore locations in the Gulf of Maine in 1966-1968 indicated that ovigerous female northern shrimp (Pandalus borealis) first appeared offshore in August and September and migrated inshore in the fall and winter. Once eggs hatched, surviving females returned offshore. Juveniles and males migrated offshore during their first two years of life. Sex transition occurred in both inshore and oll'shore waters, but most males changed sex offshore during their third and fourth years. Most shrimp changed sex and matured as females for the first time in their fourth year. Smaller females and females exposed to colder bottom temperatures spawned first. The incidence of egg parasitism peaked in January and was higher for shrimp exposed to warmer bottom temperatures. Accelerated growth at higher temperatures appeared to result in earlier or more rapid sex transition. Males and non-ovigerous females were observed to make diurnal vertical migrations, but were not found in near- surface waters where the temperature exceeded 6°C. Ovigerous females fed more heavily on benthic molluscs in inshore waters in the winter, presumably because the egg masses they were carrying prevented them from migrating vertically at night. Northern shrimp were more abundant in the southwestern region of the Gulf of Maine where bottom temperatures remain low throughout the year. Bottom trawl catch rates were highest in Jeffreys Basin where bottom temperatures were lower than at any other sampling location. Catch rates throughout the study area were inversely related to bottom temperature and reached a maximum at 3°C. An increase of 40% in fecundity between 1973 and 1979 was associated with a decline of 2-3°C in April-July offshore bottom temperatures. Furthermore, a decrease in mean fecundity per 25 mm female between 1965 and 1970 was linearly related to reduced landings between 1969 and 1974. It is hypothesized that temperature-induced changes in fecundity and, possibly, in the extent of egg mortality due to parasitism, may provide a mechanism which could partially account for changes in the size of the Gulf of Maine northern shrimp population during the last thirty years. (PDF file contains 28 pages.)

A temporal and spatial study of invertebrate communities associated with hard-bottom habitats in the South Atlantic Bight

Species composition, biomass, density, and diversity of benthic invertebrates from six bard-bottom areas were evaluated. Seasonal collections using a dredge, trawl, and suction and grab samplers yielded 432, 525, and 845 taxa, respectively. Based on collections wltb the different gear types, species composition of invertebrates was found to change bathymetrically. Inner- and mlddle-shelf sites were more similar to each other in terms of invertebrate species composition than they were to outer-shelf sites, regardless of season. Sites on the inner and outer shelf were grouped according to latitude; however, results suggest that depth is apparently a more important determinant of invertebrate species composition than either season or latitude. Sponges generally dominated dredge and trawl collections in terms of biomass. Generally, cnidarians, bryozoans, and sponges dominated at sites In terms of number of taxa collected. The most abundant smaller macrofauna collected in suction and grab samples were polychaetes, amphipods, and mollusks. Densities of the numerically dominant species changed botb seasonally and bathymetrically, with very few of these species restricted to a specific bathymetrlc zone. The high diversity of invertebrates from hard-bottom sites is attributed to the large number of rare species. No consistent seasonal changes in diversity or number of species were noted for individual stations or depth zones. In addition, H and its components showed no definite patterns related to depth or latitude. However, more species were collected at middle-shelf sites than at inner- or outer-shelf sites, which may be related to more stable bottom temperature or greater habitat complexity in that area. (PDF file contains 110 pages.)

Chaetognatha of the Caribbean Sea and adjacent areas

This illustrated manual is a guide to the distribution and identification of the 6 genera and 28 species of benthic and planktonic Chaetognatha known to occur in the Caribbean Sea, the Gulf of Mexlco, the Florida Straits, and the southwestern North Atlantic Ocean. As background, previous studies of chaetognaths in these areas are reviewed, gross morphology of the different forms is described, and instructions on methods of preserving and handling specimens preparatory to identification are provided. The key to genera and species is preceeded by a discussion of chaetognath taxonomy. A description of each species, consisting of an abbreviated synonymy, a summary of taxonomically important morphological features, and horizontal and vertical distribution follows the key. The occurrence of species in relation to water masses in the Caribbean and adjacent areas is noted. (PDF file contains 39 pages.)

The feeding ecology of some zooplankters that are important prey items of larval fish

Diets of 76 species of fish larvae from most oceans of the world were inventoried on the basis of information in 40 published studies. Although certaln geographlc, size- and taxon-specific patterns were apparent, certain zooplankton taxa appeared in the diets of larvae of a variety of fish species in numerous localities. Included were six genera of calanoid copepods (Acartia, Calanus, Centropages, Paracalanus, Pseudocaianus, Temora), three genera of cyclopoid copepods (Corycaeus, Oilhona, Oncata), harpacticoid copepods, copepod nauplii, tintinoids, cladocerans of the genera Evadne and Podon, barnacle nauplii, gastropod larvae, pteropods of the genus Limacina, and appendicularians. Literature on feeding habits of these zooplankters reveals that most of the copepods are omnivorous, feeding upon both phytoplankton and other zooplankton. Some taxa, such as Calanus, Paracalanus, Pseudocalanus, and copepod nauplii appear to be primarily herbivorous, while others, such as Acartia, Centropages, Temora, and cyclopoids exhibit broad omnivory or carnivory. The noncopepod zooplankters are primarily filter-feeders upon pbytoplankton and/or bacterioplankton. Despite the importance of zooplankters in larval fish food webs, spectic knowledge of the feeding ecology of many taxa is poor. Further, much present knowledge comes only from laboratory investigations that may not accurately portray feeding habits of zooplankters in nature. Lack of knowledge of the feeding ecology of many abundant zooplankters, which are also important in larval fish food webs, precludes realistic understanding of pelagic ecosystem dynamics. (PDF file contains 34 pages.)

Effects of macrobenthos on sediment-water oxygen and ammonium fluxes. Final Report.

Sediments are an important location in determining the fate of nutrients entering the estuary. Role of sediments needs to be incorporated into water quality models. Purpose of this study was to estimate the portion of sediment oxygen consumption (SOC) and sediment ammonium (NH4+) release directly attributable to benthic invertebrates via the respiratory use of oxygen and catabolic release of ammonium. Samples were collected at 8 locations from August 1985 through November 1988. (PDF contains 45 pages)

Biology, ecology, control and management of the invasive Indo-Pacific lionfish: An updated integrated assessment

Venomous Indo-Pacific lionfish (Pterois miles and P. volitans) are now established along the Southeast U.S.A. and parts of the Caribbean and pose a serious threat to reef fish communities of these regions. Lionfish are likely to invade the Gulf of Mexico and potentially South America in the near future. Introductions of lionfish were noted since the 1980s along south Florida and by 2000 lionfish were established off the coast of North Carolina. Lionfish are now one of the more numerous predatory reef fishes at some locations off the Southeast U.S.A. and Caribbean. Lionfish are largely piscivores that feed occasionally on economically important reef fishes. The trophic impacts of lionfish could alter the structure of native reef fish communities and potentially hamper stock rebuilding efforts of the Snapper –Grouper Complex. Additional effects of the lionfish invasion are far-reaching and could increase coral reef ecosystem stress, threaten human health, and ultimately impact the marine aquarium industry. Control strategies for lionfish are needed to mitigate impacts, especially in protected areas. This integrated assessment provides a general overview of the biology and ecology of lionfish including genetics, taxonomy, reproductive biology, early life history and dispersal, venom defense and predation, and feeding ecology. In addition, alternative management actions for mitigating the negative impacts of lionfish, approaches for reducing the risk of future invasions, and directions for future research are provided.

Observations on the taxonomy, biology, and ecology of the Engraulid and Clupeid fishes in the Gulf of Nicoya, Costa Rica.

ENGLISH: In 1952 and 1953, during the course of a study of the abrupt decline and apparent disappearance from the Gulf of Nicoya of the population of anchovetas (Cetengraulis mysticetus), an important tuna bait fish, considerable material was collected on the taxonomy, biology, and ecology of the several anchovies and the herrings inhabith1g the Gulf. The Gulf of Nicoya, approximately 50 miles long and varying in width from about 5 to 35 miles, is located on the Pacific coast of Costa Rica. The family Engraulididae is represented by four genera comprising fourteen species, and nine species were identified as members of eight genera of the family Clupeidae. All of the species inhabit other coastal areas of the tropical Eastern Pacific. SPANISH: En 1952 Y 1953, durante el curso de un estudio sobre la declinación abrupta y la aparente desaparición en el Golfo de Nicoya de la población de anchovetas (Cetengraulis mysticetus) un pez de importancia para la pesca del atún, se recolectó material considerable relacionado con la taxonomía, biología y ecología de las diversas especies de anchoas y arenques que habitan dicho Golfo. El Golfo de Nicoya, que mide aproximadamente 50 millas de largo y varía en su anchura entre 5 y 35 millas, se encuentra en la costa del Pacífico de Costa Rica. La familia de los Engráulidos está representada por cuatro géneros que comprenden catorce especies, y otras nueve fueron identificadas como miembros de ocho géneros de la familia Clupeidae. Todas estas especies habitan otras áreas costeras del Pacífico Oriental tropical. (PDF contains 144 pages.)

Effects of beach remourishment on the benthic macrofauna and the fishes of the nearshore zone at Sebastian Inlet State Recreation Area

Approximately 100,000 cubic yards of sand was transported to the ocean beach to renourish the eroded beach front during the period December 1985 through May 1986. The ocean beach at Sebastian Inlet SRA was previously studied in a project examining the benthic macrofauna and the fishes of the nearshore zone during 1981-1982 (Allenbaugh, 1984; Peters, 1984; Nelson, unpublished). In view of the existing data, the US Army Corps of Engineers provided funding to study the effects of the beach renourishment activities at Sebastian Inlet SRA on the benthic macrofauna and the fishes of the nearshore zone. This is the report on the results of this study.

The distribution, abundance, and ecology of larval tunas from the entrance to the Gulf of California

ENGLISH: This study is based on collections of larvae of Thunnus albacares, Euthynnus llneatus, and Auxis sp. obtained from surface and oblique net tows made during seven cruises, each along a comparable track in the entrance of the Gulf of California and each during a different month. Concomitant measurements of surface temperature, salinity, and zooplankton were made at each of the plankton stations. The catches of larval Auxis sp. were examined by analysis of variance techniques to determine which environmental features were associated with the spawning of this tuna as indicated by the distribution of larvae and to gain some insight into the behavior of the larvae themselves. The testing indicated that the spawning of Auxis sp. varied significantly among the different months of the cruises. The testing also indicated that if the larvae were capable of avoiding the sampling apparatus, this ability was not related to features associated with time of day such as light conditions. The analysis did not detect any change in the vertical distribution of the larvae among the months of the experiment. It was concluded that the larvae did not exhibit a diel vertical movement. The measurements of temperature, salinity, and zooplankton volumes were treated as covariates in the analysis. The surface temperature proved to be a highly important factor in explaining the distribution of larvae, but salinity and zooplankton volumes were not. Catches of Thunnus albaeares and Euthynnus lineatus were rare during the course of the study; these are discussed in qualitative terms with respect to the time of the year and the surface temperature. The distribution of larval tunas in the area of study was compared with the distribution of surface water masses. It appeared that these masses had no influence per se on the distribution of larvae. SPANISH: Este estudio está basado en las recolecciones de larvas de Thunnus albacares, Eutbynnus lineatus, y Auxis sp. obtenidas según los arrastres superficiales y oblicuos de la red, realizados durante siete cruceros, cada uno a la entrada del Golfo de California a lo largo de un derrotero comparable, y cada uno durante distintos meses. Las mediciones correspondientes de la temperatura superficial, salinidad y de zooplancton se realizaron en cada una de las estaciones de plancton. Las capturas de larvas Auxís sp. fueron examinadas mediante el análisis de la varianza para determinar cuales características ambientales se encontraban asociadas con el desove de este atún según lo indicaba la distribución de las larvas, y para obtener alguna idea del comportamiento de las larvas en sí mismas. Las pruebas indicaron que el desove de Auxis sp. varió significativamente entre los diferentes meses de los cruceros; indicaron también que si las larvas eran capaces de evitar el aparato de muestreo, esta habilidad no se relacionaba a las características asociadas con la hora del día de acuerdo a las condiciones de luz. El análisis no demostró ningún cambio en la distribución vertical de las larvas durante los meses del experimento. Se determinó que las larvas no exhiben un movimiento vertical diario. Las mediciones de temperatura, salinidad, y de los volúmenes de zooplancton fueron tratadas como covariables en el análisis. La temperatura superficial demostró ser un factor altamente importante en la explicación de la distribución de las larvas, pero la salinidad y los volúmenes de zooplancton no lo fueron. Las capturas de Thunnus albacares y Eutbynnus lineatus fueron pocas durante el curso de este estudio; éstas se discuten en términos cualitativos respecto a la época del año y a la temperatura superficial. La distribución de los atunes larvales en el área de estudio fue comparada con la distribución de las masas superficiales de agua. Parece que estas masas no tienen influencia per se en la distribución de las larvas. (PDF contains 40 pages.)

Entweicht Radioaktivität aus den Abfallfässern im nordostatlantischen Versenkungsgebiet?

Radioactivity measured in samples from the NEA-Dumping-Site not only emanated from dumped barrels. Just as everywhere on the world also fallout from former nuclear weapon tests can be found there. Radionuclides which can emanate from different sources do not tell anything about their origin. To assess the fractions from various sources activity ratios from radionuclides can be used. There are different activity ratios for fallout and for waste from peaceful nuclear power engeneering. The comparison of the ratios of the plutonium isotopes Pu-238 and the sum of Pu-239 and Pu-240 (Pu-238/Pu-239,240) in benthic samples from the dumping site and from reference sites without waste dumping gives a clear hint. In the sampling period from 1980 to 2000 for samples from the dumping site this ratio increases significantly from 1986 on. Radioactivity emanating from the dumped barrels is regarded as causing this.

Ichthyoplanktonaufnahmen als Beitrag zu Biodiversitätsuntersuchungen in der westlichen Ostsee

Ichthyoplankton material provides information on the species composition in an area of investigation and leads to a better understanding of the entire fish community. Since 1993 every year in May and/or June an ichthyoplankton survey in ICES-Subdivision 22 and 24 has been performed to sample the plankton community of fishery resources in the western Baltic Sea. One objective was to get signs of possible changes in the natural structures of this fish community. The time series derived from the Bongo-Net samples does not show a clear trend in larval densities. Values varied, but up to now samplings in the western Baltic Sea yielded only low mean densities. According to the kind of reproductive biology the fish species were divided in three major groups: • Fish species with a long developmental phase in the plankton community • Small short living species with benthic eggs and a reduced plankton phase • Guests without local spawning populations. Species could be identified, which were absent in the fish larvae catches of the western Baltic Sea in the 60s and 70s.

Panama City Fisheries Resources Office: FY 2005 Annual Report

HIGHLIGHTS FOR FY 2005 1. Assisted with a study to assess hurricane impacts to Gulf sturgeon critical foraging habitat. 2. Documented Gulf sturgeon marine movement and habitat use in the Gulf of Mexico. 3. Documented Gulf sturgeon spawning with the collection of fertilized eggs in the Apalachicola River, Florida. 4. Documented Gulf sturgeon spawning with the collection of fertilized eggs in the Yellow River, Florida. 5. Assisted with benthic invertebrate survey at Gulf sturgeon marine foraging grounds. 6. Implemented Gulf Striped Bass Restoration Plan by coordinating the 22nd Annual Morone Workshop, leading the technical committee, transporting broodfish, and coordinating the stocking on the Apalachicola-Chattahoochee-Flint (ACF) river system. 7. Over 87,000 Phase II Gulf striped bass were marked with sequential coded wire tags and stocked in the Apalachicola River. Post-stocking evaluations were conducted at 45 sites in the fall and spring and 8 thermal refuges in the summer. 8. Completed fishery surveys on 4 ponds on Eglin AFB totaling 53 acres, and completed a report with recommendations for future recreational fishery needs. 9. Completed final report for aquatic monitoring at Eglin AFB from 1999 to 2004. 10. Completed a field collection of the endangered Okaloosa darter to be incorporated into a status review to be completed in FY06. 11. Provided technical assistance to the Region 4 National Wildlife Refuge (NWR) program on changes to the fishery conservation targets for the region. Also provided technical assistance to four NWRs (i.e., Okefenokee NWR, Banks Lake NWR, St. Vincent NWR, and St. Marks NWR) relative to hurricanes and recreational fishing. 12. A draft mussel sampling protocol was tested in wadeable streams in Northwest Florida and southwest Georgia, and an associated field guide, poster, and Freshwater Mussel Survey Protocol and Identification workshop were completed in FY05. 13. Implemented recovery plan and candidate conservation actions for 14 listed and candidate freshwater mussels in the Northeast Gulf Watersheds. 14. Initiated or completed multiple stream restoration and watershed management projects. A total of 7.5 stream miles were restored for stream fishes, and 11 miles of coastline were enhanced for sea turtle lighting. A total of 630 acres of wetlands and 2,401 acres of understory habitat were restored. 15. Conducted a watershed assessment to develop a threats analysis for prioritizing restoration, protection, and enhancement to natural resources of Spring Creek, Georgia and Canoe Creek, Florida. 16. Continued the formation of an Unpaved Road Interagency Team of Federal, State, and local agencies in Northwest Florida to promote stream protection and restoration from unpaved road sediment runoff. Began the development of a technical committee agreement. 17. Conducted Alabama Unpaved Road Inventory within the Northeast Gulf Ecosystem. Data collection will be completed during FY06. 18. Finalized the development of two North Florida hydrophysiographic regional curves for use by the Florida Department of Transportation (DOT) and others involved with stream restoration and protection. Initiated the development of the Alabama Coastal Plain Riparian Reference Reach and Regional Curves for use by the Alabama Department of Environmental Management (ADEM). 19. Provided technical assistance in collecting data, analysis, and thesis formulation with Troy University, Alabama, to identify the influence of large woody debris in southeastern coastal plain streams. 20. Completed pre- and post-restoration fish community monitoring at several restoration projects including Big Escambia Creek, Magnolia Creek, and Oyster Lake, Florida. 21. Established a watershed partnership for the Chipola River in Alabama and Florida and expanded development and participation in the Spring Creek Watershed Partnership, Georgia. 22. Continued to identify barriers which inhibit the movement of aquatic species within the Northeast Gulf Ecoregion. 23. Completed a report on road crossing structures in Okaloosa darter streams to guide the closure/repair/maintenance of roads to contribute to recovery of the endangered species. In cooperation with Three Rivers RC&D Council, fish passage sites identified in the report were prioritized for restoration. 24. Monitored Aquatic Nuisance Species in the Apalachicola River and tested the sterility of exotic grass carp. 25. Multiple outreach projects were completed to detail aquatic resources conservation needs and opportunities. Participated in National Fishing Week event, several festivals, and school outreach.