Mark Hamann

Global Conservation Priorities for Marine Turtles

Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widely distributed and exhibit intra-specific variations in population sizes and trends, as well as reproduction and morphology. However, current global extinction risk assessment frameworks do not assess conservation status of spatially and biologically distinct marine turtle Regional Management Units (RMUs), and thus do not capture variations in population trends, impacts of threats, or necessary conservation actions across individual populations. To address this issue, we developed a new assessment framework that allowed us to evaluate, compare and organize marine turtle RMUs according to status and threats criteria. Because conservation priorities can vary widely (i.e. from avoiding imminent extinction to maintaining long-term monitoring efforts) we developed a “conservation priorities portfolio” system using categories of paired risk and threats scores for all RMUs (n = 58). We performed these assessments and rankings globally, by species, by ocean basin, and by recognized geopolitical bodies to identify patterns in risk, threats, and data gaps at different scales. This process resulted in characterization of risk and threats to all marine turtle RMUs, including identification of the worlds 11 most endangered marine turtle RMUs based on highest risk and threats scores. This system also highlighted important gaps in available information that is crucial for accurate conservation assessments. Overall, this priority-setting framework can provide guidance for research and conservation priorities at multiple relevant scales, and should serve as a model for conservation status assessments and priority-setting for widespread, long-lived taxa.

Regional Management Units for Marine Turtles: A Novel Framework for Prioritizing Conservation and Research across Multiple Scales

Background Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques — including site-based monitoring, genetic analyses, mark-recapture studies and telemetry — can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges. Methodology/Principal Findings To address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine- to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally. Conclusions/Significance The RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework — including maps and supporting metadata — will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis.

Monitoring Bacterial Diversity of the Marine Sponge Ircinia strobilina upon Transfer into Aquaculture

ABSTRACT Marine sponges in the genus Ircinia are known to be good sources of secondary metabolites with biological activities. A major obstacle in the development of sponge-derived metabolites is the difficulty in ensuring an economic, sustainable supply of the metabolites. A promising strategy is the ex situ culture of sponges in closed or semiclosed aquaculture systems. In this study, the marine sponge Ircinia strobilina (order Dictyoceratida: family Irciniidae) was collected from the wild and maintained for a year in a recirculating aquaculture system. Microbiological and molecular community analyses were performed on freshly collected sponges and sponges maintained in aquaculture for 3 months and 9 months. Chemical analyses were performed on wild collected sponges and individuals maintained in aquaculture for 3 months and 1 year. Denaturing gradient gel electrophoresis was used to assess the complexity of and to monitor changes in the microbial communities associated with I. strobilina. Culture-based and molecular techniques showed an increase in the Bacteroidetes and Alpha- and Gammaproteobacteria components of the bacterial community in aquaculture. Populations affiliated with Beta- and Deltaproteobacteria, Clostridia, and Planctomycetes emerged in sponges maintained in aquaculture. The diversity of bacterial communities increased upon transfer into aquaculture.

Structure and absolute configuration of karlotoxin-2, an ichthyotoxin from the marine dinoflagellate Karlodinium veneficum.

In an attempt to determine the cause of repeated fish kills in an estuarine aquaculture facility in Maryland, a toxin with hemolytic, cytotoxic, and ichthyotoxic properties, designated as karlotoxin-2 (KmTx2), was isolated from Karlodinium veneficum. The structure of KmTx2 was elucidated by means of detailed ID and 2D NMR spectra, including 2D INADEQUATE. The relative and absolute configurations of KmTx2 were determined using J-based configuration analysis and comparison of its degradation products with synthetic controls.

Mollamides B and C, Cyclic Hexapeptides from the Indonesian Tunicate Didemnum molle

Two new cyclic hexapeptides, mollamides B (1) and C (2), were isolated from the Indonesian tunicate Didemnum molle along with the known peptide keenamide A (3). The structures were established using 1D and 2D NMR experiments. The relative configuration of mollamide B at the thiazoline moiety was determined using molecular modeling coupled with NMR-derived restraints. Their absolute configuration was determined using Marfeyʼs method. The new peptides have been evaluated for their antimicrobial, antimalarial, anticancer, anti-HIV-1, anti-Mtb, and anti-inflammatory activities. Keenamide A and mollamide B show cytotoxicity against several cancer cell lines.

Interplay between age class, sex and stress response in green turtles (Chelonia mydas)

We investigated plasma hormone profiles of corticosterone in green turtles (Chelonia mydas) in response to a capture stress protocol. Further, we examined whether age class and sex were covariates associated with variation in both basal corticosterone levels and the adrenocortical stress response of non-breeding green turtles. Green turtles responded to the capture stress protocol by significantly increasing plasma levels of corticosterone over an eight-hour period. Further, there was a significant effect of age class on the capacity for green turtles to produce corticosterone in response to a capture stressor, with juvenile green turtles having higher basal levels of corticosterone and producing significantly more corticosterone in response to capture stress than non-breeding adult turtles. In contrast there was no significant sex difference in the corticosterone stress response of green turtles irrespective of age class. In summary, green turtles exhibited an adrenocortical response to a capture stress protocol. This response was significantly associated with different age classes, perhaps suggesting that the response is increased in juvenile turtles to offset the reduced probability of survival consistent with this more vulnerable age class.

Satellite Tracking of Sympatric Marine Megafauna Can Inform the Biological Basis for Species Co-Management

Context Systematic conservation planning is increasingly used to identify priority areas for protection in marine systems. However, ecosystem-based approaches typically use density estimates as surrogates for animal presence and spatial modeling to identify areas for protection and may not take into account daily or seasonal movements of animals. Additionally, sympatric and inter-related species are often managed separately, which may not be cost-effective. This study aims to demonstrate an evidence-based method to inform the biological basis for co-management of two sympatric species, dugongs and green sea turtles. This approach can then be used in conservation planning to delineate areas to maximize species protection. Methodology/Results Fast-acquisition satellite telemetry was used to track eleven dugongs and ten green turtles at two geographically distinct foraging locations in Queensland, Australia to evaluate the inter- and intra-species spatial relationships and assess the efficacy of existing protection zones. Home-range analysis and bathymetric modeling were used to determine spatial use and compared with existing protection areas using GIS. Dugong and green turtle home-ranges significantly overlapped in both locations. However, both species used different core areas and differences existed between regions in depth zone use and home-range size, especially for dugongs. Both species used existing protection areas in Shoalwater Bay, but only a single tracked dugong used the existing protection area in Torres Strait. Conclusions/Significance: Fast-acquisition satellite telemetry can provide evidence-based information on individual animal movements to delineate relationships between dugongs and green turtles in regions where they co-occur. This information can be used to increase the efficacy of conservation planning and complement more broadly based survey information. These species also use similar habitats, making complimentary co-management possible, but important differences exist between locations making it essential to customize management. This methodology could be applied on a broader scale to include other sympatric and inter-related species.

Kahalalides V–Y Isolated from a Hawaiian Collection of the Sacoglossan Mollusk Elysia rufescens

Four new kahalalides, V (1), W (2), X (3), and Y (4), as well as six previously characterized kahalalides have been isolated from a two-year collection of the sacoglossan mollusk Elysia rufescens. Curiously, kahalalide B, previously isolated in high yield from E. rufescens, was found to be essentially absent from these collections despite identical collection sites and times with previous collections. In addition, kahalalide K, which to date has only been reported from Bryopsis sp., was found in this collection of E. rufescens, suggesting that the production of these metabolites could potentially be from a microbial association with the mollusk and algae, and this relationship is continuously evolving in response to changes in the environment and predation. The structures of new peptides have been established on the basis of extensive 1D and 2D NMR spectroscopic data analysis. Kahalalide V (1) was ascertained to be an acyclic derivative of kahalalide D (5), while kahalalide W (2) was determined to have a 4-hydroxy-L-proline residue instead of the proline in 5. The arginine residue of kahalalide X (3), an acyclic derivative of kahalalide C, was determined to have an L configuration. Kahalalide Y (4) was found to have an L-proline residue instead of the hydroxyproline in kahalalide K. It is clear from this collection of E. rufescens that the discovery of new kahalalide-related metabolites is still highly feasible.

Rezoning of the Great Barrier Reef World Heritage Area: does it afford greater protection for marine turtles?

In 2004 the Australian Government implemented a revised zone-based management plan for the Great Barrier Reef World Heritage Area to increase protection of representative areas while minimising the impacts to the economic viability of important industries. In this study we evaluated the current zoning plan for its capacity to protect marine turtles from commercial trawling and netting activities at nesting sites and at inshore and offshore foraging areas to assess whether the Great Barrier Reef Marine Park Authority met their obligations under the Representative Areas Program (RAP). We found that protection from commercial fisheries increased within 5- and 10-km buffer zones of all very-high, high- and medium-priority nesting sites that were previously less than 100% protected. However, three very-high-priority sites and six high-priority sites remain less than 100% protected out to 5 km, falling short of the objectives of the RAP. There were variable increases in protection at foraging areas; however, each of them increased in the proportion of area protected from commercial fishing, fulfilling the objectives of the RAP. By using a broader-scale fisheries by-catch dataset as a proxy for turtle abundance we found that improvements in protection are not species-specific and can be attributed to the step-wise increases in protection since the mid 1990s.

Role of Marine Natural Products in the Genesis of Antiviral Agents

Mammals have complex biological systems and are constantly prone to infections by a wide array of bacteria, fungi, viruses, and parasites, a significant challenge to the constant development of disease-strains resistance to current drugs.1 As a result, there is always a need to identify new anti-infective agents against these organisms. An anti-infective agent is defined by Webster as “an agent capable of acting against an infection, by inhibiting the spread of an infectious agent or by killing the infectious agent outright”.2 Some of the emerging and drug-resistant infectious diseases having research priority are human immunodeficiency virus (HIV) or AIDS, hepatitis B and C viruses, respiratory infections such as influenza and respiratory syncytial virus (RSV), and dengue fever.1 Figures 1 and ​and22 provide us with the data in regards to the mortality and incidence rates, respectively, of people with viral diseases.3–5 Figure 1 Mortality versus viral diseases.3–5 Figure 2 Incidence rates versus viral diseases.3–5 Search engines utilized to identify the literature reviewed here include Google scholar, Scifinder, Pubmed, government documents from the CDC, NIH, and the World Health Organization (WHO), academic journals, and books.