Tropical forest history of the Ecuadorian Andes over the last 34,000 years: preliminary results from pollen and oxygen isotope analyses of Trident 163-13 from the eastern equatorial Pacific [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Pollen from the upper 2.75 m of a core taken 200 km west of the Golfo de Guayaquil, Ecuador (Trident 163-13, 3° S, 84° W, 3,000 m water depth) documents changes in Andean vegetation and climate of the Cordillera Occidental for ~17,000 years before and after the last glacial maximum.

Holocene climate and El Nino history as recorded in the sediments of northern coastal Peru [abstract, table, and references]

EXTRACT (SEE PDF FOR FULL ABSTRACT): The history of the El Nino phenomena is recorded in both the fluvial and coastal sediments of northern Peru. The fluvial record was presented at the 1987 PACLIM Workshop and is discussed in detail elsewhere (Wells, 1987). However, the number of radiocarbon dated El Nino events has increased since Wells (1987) was published; this data is presented in Table 1.

Reducing sea turtle bycatch in trawl nets: a history of NMFS turtle excluder device (TED) research

Thirty-six years ago, NOAA’s National Marine Fisheries Service began research on how to reduce mortality of sea turtles, Chelonioidea, in shrimp trawls. As a result of efforts of NMFS and many stakeholders, including domestic and foreign fishermen, environmentalists, Sea Grant agents, and government agencies, many trawl fisheries around the world use a version of the turtle excluder device (TED). This article chronicles the contributions of NMFS to this effort, much of which occurred at the NMFS Mississippi Laboratories in Pascagoula. Specifically, it summarizes the impetus for and results of major developments and little known events in the TED research and discusses how these influenced the course of subsequent research.

An assessment of chemical contaminants, toxicity and benthic infauna in sediments from the St. Thomas East End Reserves (STEER)

This report contains a chemical and biological characterization of sediments from the St. Thomas East End Reserves (STEER) in St. Thomas, U.S. Virgin Islands (USVI). The STEER Management Plan (published in 2011) identified chemical contaminants and habitat loss as high or very high threats and called for a characterization of chemical contaminants as well as an assessment of their effects on natural resources. The baseline information contained in this report on chemical contaminants, toxicity and benthic infaunal community composition can be used to assess current conditions, as well as the efficacy of future restoration activities. In this phase of the project, 185 chemical contaminants, including a number of organic (e.g., hydrocarbons and pesticides) and inorganic (e.g., metals) compounds, were analyzed from 24 sites in the STEER. Sediments were also analyzed using a series of toxicity bioassays, including amphipod mortality, sea urchin fertilization impairment, and the cytochrome P450 Human Reporter Gene System (HRGS), along with a characterization of the benthic infaunal community. Higher levels of chemical contaminants were found in Mangrove Lagoon and Benner Bay in the western portion of the study area than in the eastern area. The concentrations of polychlorinated biphenyls (PCBs), DDT (dichlorodiphenyltrichloroethane), chlordane, zinc, copper, lead and mercury were above a NOAA sediment quality guideline at one or more sites, indicating impacts may be present in more sensitive species or life stages in the benthic environment. Copper at one site in Benner Bay, however, was above a NOAA guideline indicating that effects on benthic organisms were likely. The antifoulant boat hull ingredient tributyltin, or TBT, was found at the third highest concentration in the history of NOAA’s National Status and Trends (NS&T) Program, which monitors the Nation’s coastal and estuarine waters for chemical contaminants and bioeffects. Unfortunately, there do not appear to be any established sediment quality guidelines for TBT. Results of the bioassays indicated significant sediment toxicity in Mangrove Lagoon and Benner Bay using multiple tests. The benthic infaunal communities in Mangrove Lagoon and Benner Bay appeared severely diminished.

Report of 2009 Bottlenose Dolphin (Tursiops truncatus) Life History Workshop: expanding network capabilities

The Virginia Aquarium & Marine Science Center Foundation’s Stranding Response Program (VAQS) was awarded a grant in 2008 to conduct life history analysis on over 10 years of Tursiops truncatus teeth and gonad samples from stranded animals in Virginia. A major part of this collaborative grant included a workshop involving life historians from Hubbs-Sea World Research Institute (HSWRI), NOS, Texas A & M University (TAMU), and University of North Carolina Wilmington (UNCW). The workshop was held at the NOAA Center for Coastal Environmental Health & Biomolecular Research in Charleston, SC on 7-9 July 2009. The workshop convened to 1) address current practices among the groups conducting life history analysis, 2) decide on protocols to follow for the collaborative Prescott grant between VAQS and HSWRI, 3) demonstrate tissue preparation techniques and discuss shortcuts and pitfalls, 4) demonstrate data collection from prepared testes, ovaries, and teeth, and 5) discuss data analysis and prepare an outline and timeline for a future manuscript. The workshop concluded with discussions concerning the current collaborative Tursiops Life History Prescott grant award and the beginnings of a collaborative Prescott proposal with members of the Alliance of Marine Mammal Parks and Aquariums to further clarify reproductive analyses. This technical memorandum serves as a record of this workshop.

Combining stable isotopes and skeletal growth marks to detect habitat shifts in juvenile loggerhead sea turtles Caretta caretta

Understanding the phase and timing of ontogenetic habitat shifts underlies the study of a species’ life history and population dynamics. This information is especially critical to the conservation and management of threatened and endangered species, such as the loggerhead sea turtle Caretta caretta. The early life of loggerheads consists of a terrestrial egg and hatchling stage, a posthatchling and juvenile oceanic, pelagic feeding stage, and a juvenile neritic, primarily benthic feeding stage. In the present study, novel approaches were applied to explore the timing of the loggerhead ontogenetic shift from pelagic to benthic habitats. The most recent years of somatic growth are recorded as annual marks in humerus cross sections. A consistent growth mark pattern in benthic juvenile loggerheads was identified, with narrow growth marks in the interior of the bone transitioning to wider growth marks at the exterior, indicative of a sharp increase in growth rates at the transitional growth mark. This increase in annual growth is hypothesized to correlate with the ontogenetic shift from pelagic to benthic habitats. Stable isotopes of carbon and nitrogen just interior and exterior to the transitional growth mark, as well as stable isotopes from pelagic and benthic flora, fauna and loggerhead stomach contents, were analyzed to determine whether this transition related to a diet shift. The results clearly indicate that a dietary shift from oceanic/pelagic to neritic/benthic feeding corresponds to a transitional growth mark. The combination of stable isotope analysis with skeletochronology can elucidate the ecology of cryptic life history stages during loggerhead ontogeny.

Azaspiracid shellfish poisoning: a review on the chemistry, ecology, and toxicology with an emphasis on human health impacts

Azaspiracids (AZA) are polyether marine toxins that accumulate in various shellfish species and have been associated with severe gastrointestinal human intoxications since 1995. This toxin class has since been reported from several countries, including Morocco and much of western Europe. A regulatory limit of 160 μg AZA/kg whole shellfish flesh was established by the EU in order to protect human health; however, in some cases, AZA concentrations far exceed the action level. Herein we discuss recent advances on the chemistry of various AZA analogs, review the ecology of AZAs, including the putative progenitor algal species, collectively interpret the in vitro and in vivo data on the toxicology of AZAs relating to human health issues, and outline the European legislature associated with AZAs.

Radiometric validation of age, growth, and longevity for the blackgill rockfish (Sebastes melanostomus)

As nearshore fish populations decline, many commercial fishermen have shifted fishing effort to deeper continental slope habitats to target fishes for which biological information is limited. One such fishery that developed in the northeastern Pacific Ocean in the early 1980s was for the blackgill rockfish (Sebastes melanostomus), a deep-dwelling (300−800 m) species that congregates over rocky pinnacles, mainly from southern California to southern Oregon. Growth zone-derived age estimates from otolith thin sections were compared to ages obtained from the radioactive disequilibria of 210Pb, in relation to its parent, 226Ra, in otolith cores of blackgill rockfish. Age estimates were validated up to 41 years, and a strong pattern of agreement supported a longevity exceeding 90 years. Age and length data fitted to the von Bertalanffy growth function indicated that blackgill rockfish are slow-growing (k= 0.040 females, 0.068 males) and that females grow slower than males, but reach a greater length. Age at 50% maturity, derived from previously published length-at-maturity estimates, was 17 years for males and 21 years for females. The results of this study agree with general life history traits already recognized for many Sebastes species, such as long life, slow growth, and late age at maturation. These traits may undermine the sustainability of blackgill rockfish populations when heavy fishing pressure, such as that which occurred in the 1980s, is applied.

Life history of the Atlantic sharpnose shark (Rhizoprionodon terraenovae) (Richardson, 1836) off the southeastern United States

The life history of the Atlantic sharpnose shark (Rhizoprionodon terraenovae) was described from 1093 specimens collected from Virginia to northern Florida between April 1997 and March 1999. Longitudinally sectioned vertebral centra were used to age each specimen, and the periodicity of circuli deposition was verified through marginal increment analysis and focus-to-increment frequency distributions. Rhizoprionodon terraenovae reached a maximum size of 828 mm precaudal length (PCL) and a maximum age of 11+ years. Mean back-calculated lengths-at-age ranged from 445 mm PCL at age one to 785 mm PCL at age ten for females, and 448 mm PCL at age one to 747 mm PCL at age nine for males. Observed lengthat-age data (estimated to 0.1 year) yielded the following von Bertalanffy parameters estimates: L∞= 749 mm PCL (SE=4.60), K = 0.49 (SE=0.020), and t0= –0.94 (SE=0.046) for females; and L∞= 745 mm PCL (SE = 5.93), K = 0.50 (SE=0.024), and t0= –0.91 (SE = 0.052) for males. Sexual maturity was reached at age three and 611 mm PCL for females, and age three and 615 mm PCL for males. Rhizoprionodon terraenovae reproduced annually and had a gestation period of approximately 11 months. Litter size ranged from one to eight (mean=3.85) embyros, and increased with female PCL.

Life history and population dynamics of the finetooth shark (Carcharhinus isodon) in the northeastern Gulf of Mexico

The life history and population dynamics of the finetooth shark (Carcharhinus isodon) in the north-eastern Gulf of Mexico were studied by determining age, growth, size-at-maturity, natural mortality, productivity, and elasticity of vital rates of the population. The von Bertalanffy growth model was estimated as Lt=1559 mm TL (1–e–0.24 (t+2.07)) for females and Lt = 1337 mm TL (1–e–0.41 (t+1.39)) for males. For comparison, the Fabens growth equation was also fitted separately to observed size-at-age data, and the fits to the data were found to be similar. The oldest aged specimens were 8.0 and 8.1 yr, and theoretical longevity estimates were 14.4 and 8.5 yr for females and males, respectively. Median length at maturity was 1187 and 1230 mm TL, equivalent to 3.9 and 4.3 yr for males and females, respectively. Two scenarios, based on the results of the two equations used to describe growth, were considered for population modeling and the results were similar. Annual rates of survivorship estimated through five methods ranged from 0.850/yr to 0.607/yr for scenario 1 and from 0.840/yr to 0.590/yr for scenario 2. Productivities were 0.041/yr for scenario 1 and 0.038/yr for scenario 2 when the population level that produces maximum sustain-able yield is assumed to occur at an instantaneous total mortality rate (Z) equaling 1.5 M, and were 0.071/yr and 0.067/yr, when Z=2 M for scenario 1 and 2, respectively. Mean generation time was 6.96 yr and 6.34 yr for scenarios 1 and 2, respectively. Elasticities calculated through simulation of Leslie matrices averaged 12.6% (12.1% for scenario 2) for fertility, 47.7% (46.2% for scenario 2) for juvenile survival, and 39.7% (41.6% for scenario 2) for adult survival. In all, the finetooth shark exhibits life-history and population characteristics intermediate to those of sharks in the small coastal complex and those from some large coastal species, such as the blacktip shark (Carcharhinus limbatus).

Effect of analytical conditions in wavelength dispersive electron microprobe analysis on the measurement of strontium-to-calcium (Sr/Ca) ratios in otoliths of anadromous salmonids

The use of strontium-to-calcium (Sr/Ca) ratios in otoliths is becoming a standard method to describe life history type and the chronology of migrations between freshwater and seawater habitats in teleosts (e.g. Kalish, 1990; Radtke et al., 1990; Secor, 1992; Rieman et al., 1994; Radtke, 1995; Limburg, 1995; Tzeng et al. 1997; Volk et al., 2000; Zimmerman, 2000; Zimmerman and Reeves, 2000, 2002). This method provides critical information concerning the relationship and ecology of species exhibiting phenotypic variation in migratory behavior (Kalish, 1990; Secor, 1999). Methods and procedures, however, vary among laboratories because a standard method or protocol for measurement of Sr in otoliths does not exist. In this note, we examine the variations in analytical conditions in an effort to increase precision of Sr/Ca measurements. From these findings we argue that precision can be maximized with higher beam current (although there is specimen damage) than previously recommended by Gunn et al. (1992).

The early life history of swordfish (Xiphias gladius) in the western North Atlantic

Lengths and ages of sword-fish (Xiphias gladius) estimated from increments on otoliths of larvae collected in the Caribbean Sea, Florida Straits, and off the southeastern United States, indicated two growth phases. Larvae complete yolk and oil globule absorption 5 to 6 days after hatching (DAH). Larvae <13 mm preserved standard length (PSL) grow slowly (~0.3 mm/d); larvae from 13 to 115 mm PSL grow rapidly (~6 mm/d). The acceleration in growth rate at 13 days follows an abrupt (within 3 days) change in diet, and in jaw and alimentary canal structure. The diet of swordfish larvae is limited. Larvae <8 mm PSL from the Caribbean, Gulf of Mexico, and off the southeastern United States eat exclusively copepods, primarily of one genus, Corycaeus. Larvae 9 to 11 mm eat copepods and chaetognaths; larvae >11 mm eat exclusively neustonic fish larvae. This diet indicates that young larvae <11 mm occupy the near-surface pelagia, whereas, older and longer larvae are neustonic. Spawning dates for larvae collected in various regions of the western North Atlantic, along with the abundance and spatial distribution of the youngest larvae, indicate that spawning peaks in three seasons and in five regions. Swordfish spawn in the Caribbean Sea, or possibly to the east, in winter, and in the western Gulf of Mexico in spring. Elsewhere swordfish spawn year-round, but spawning peaks in the spring in the north-central Gulf of Mexico, in the summer off southern Florida, and in the spring and early summer off the southeastern United States. The western Gulf Stream frontal zone is the focus of spawning off the southeastern coast of the United States, whereas spawning in the Gulf of Mexico seems to be focused in the vicinity of the Gulf Loop Current. Larvae may use the Gulf of Mexico and the outer continental shelf off the east coast of the United States as nursery areas. Some larvae may be transported northward, but trans-Atlantic transport of larvae is unlikely.

Nuclear and mitochondrial DNA markers for specific identification of istiophorid and xiphiid billfishes

Independent molecular markers based on mitochondrial and nuclear DNA were developed to provide positive identification of istiophorid and xiphiid billfishes (marlins, spearfishes, sailfish, and swordfish). Both classes of markers were based on amplification of short segments (<1.7 kb) of DNA by the polymerase chain reaction and subsequent digestion with informative restriction endonucleases. Candidate markers were evaluated for their ability to discriminate among the different species and the level of intraspecific variation they exhibited. The selected markers require no more than two restriction digestions to allow unambiguous identification, although it was not possible to distinguish between white marlin and striped marlin with any of the genetic characters screened in our study. Individuals collected from throughout each species’ range were surveyed with the selected markers demonstrating low levels of intraspecific character variation within species. The resulting keys provide two independent means for the forensic identification of fillets and for specific identification of early life history stages.

Life history of South African snoek, Thyrsites atun (Pisces: Gempylidae): a pelagic predator of the Benguela ecosystem

Snoek (Thyrsites atun) is a valuable commercial species and an important predator of small pelagic fishes in the Benguela ecosystem. The South African population attains 50% sexual maturity at a fork length of ca.73.0 cm (3 years). Spawning occurs offshore during winter−spring, along the shelf break (150–400 m) of the western Agulhas Bank and the South African west coast. Prevailing currents transport eggs and larvae to a primary nursery ground north of Cape Columbine and to a secondary nursery area to the east of Danger Point; both shallower than 150 m. Juveniles remain on the nursery grounds until maturity, growing to between 33 and 44 cm in the first year (3.25 cm/month). Onshore– offshore distribution (between 5- and 150-m isobaths) of juveniles is deter-mined largely by prey availability and includes a seasonal inshore migration in autumn in response to clupeoid recruitment. Adults are found through-out the distribution range of the species, and although they move offshore to spawn—there is some southward dispersion as the spawning season progresses—longshore movement is apparently random and without a seasonal basis. Relative condition of both sexes declined dramatically with the onset of spawning. Mesenteric fat loss was, however, higher in females, despite a greater rate of prey consumption. Spatial differences in sex ratios and indices of prey consumption suggest that females on the west coast move inshore to feed between spawning events, but that those found farther south along the western Agulhas Bank remain on the spawning ground throughout the spawning season. This regional difference in female behavior is attributed to higher offshore abundance of clupeid prey on the western Agulhas Bank, as determined from both diet and rates of prey consumption.