The role of ethics in experimental marine biology and ecology

Although most countries have ethical guidelines for research involving human subjects and other sentient animals, the ethical issues associated with field research have received little attention. Most experimental marine biologists and ecologists operate without ethical guidelines or scrutiny, despite intermittent community concern about their activities. We offer suggestions on how marine biologists and ecologists can protect the future of research involving the field collection and experimental manipulation of organisms by developing mechanisms to address community concerns that such research is ethically responsible. We urge experimental marine biologists and ecologists to take pre-emptive initiatives by encouraging: (1) institutional animal ethics committees to broaden their terms of reference to include environmental ethics; (2) scientific societies to develop codes of ethics to guide the environmental research conducted by their members; (3) editorial boards of journals to require the research they publish to conform to an appropriate code of ethics, and (4) management agencies that issue permits for field research to establish an ethics committee to advise them on the ethical issues raised by specific research proposals. We conclude that the resultant administrative burden on scientists would be low but that the penalties of operating without such protection can be high.     

Foraging by the mud snail, Ilyanassa obsoleta (Say), modulates spatial variation in benthic community structure

We investigated the foraging behavior of the mud snail, Ilyanassa obsoleta, and its consequences for macrobenthic community structure on mud flats on Long Island, NY, USA. Field sampling demonstrated strong spatial heterogeneity in the population densities of I. obsoleta. We experimentally tested three hypotheses: (i) I. obsoleta are strongly attracted to areas with high levels of detritus; (ii) local abundances of deposit-feeding annelids are limited by detritus; and (iii) the foraging activities of I. obsoleta negatively affects annelid assemblages. We manipulated the density of mud snails using inclusion fences and the levels of detritus using dried Ulva. Results showed that high densities of I. obsoleta were attracted to areas enriched with Ulva detritus. In addition, high densities of snails negatively affected abundances of annelids, with the opportunistic species, Capitella spp. and Paranais litoralis, being most affected. The addition of Ulva detritus had more specific effects on annelid assemblages. Only Capitella spp. showed a significant positive response, although previous evidence has demonstrated that higher experimental detrital inputs stimulated growth of other species of annelids and microphytobenthos. In an experimental treatment with enhanced detritus and low densities of snails, we found population abundances of opportunistic annelids (up to 200,000 m⁻²) substantially larger than has ever been recorded in 5 years of sampling. Because mud snails in natural areas actively search, locate and exploit areas with enhanced detritus and their foraging negatively affects abundances of opportunistic worms, I. obsoleta probably controls the upper limits of annelid abundance in the field. Foraging behavior of I. obsoleta therefore modulates spatial variation in benthic community structure in an environment where limiting resources are patchily distributed.     

Development and validation of an experimental life support system for assessing the effects of global climate change and environmental contamination on estuarine and coastal marine benthic communities

An experimental life support system (ELSS) was constructed to study the interactive effects of multiple stressors on coastal and estuarine benthic communities, specifically perturbations driven by global climate change and anthropogenic environmental contamination. The ELSS allows researchers to control salinity, pH, temperature, ultraviolet radiation (UVR), tidal rhythms and exposure to selected contaminants. Unlike most microcosms previously described, our system enables true independent replication (including randomization). In addition to this, it can be assembled using commercially available materials and equipment, thereby facilitating the replication of identical experimental setups in different geographical locations. Here, we validate the reproducibility and environmental quality of the system by comparing chemical and biological parameters recorded in our ELSS with those prevalent in the natural environment. Water, sediment microbial community and ragworm (the polychaete Hediste diversicolor) samples were obtained from four microcosms after 57 days of operation. In general, average concentrations of dissolved inorganic nutrients (NO₃^?; NH₄⁺ and PO₄^?3) in the water column of the ELSS experimental control units were within the range of concentrations recorded in the natural environment. While some shifts in bacterial community composition were observed between in situ and ELSS sediment samples, the relative abundance of most metabolically active bacterial taxa appeared to be stable. In addition, ELSS operation did not significantly affect survival, oxidative stress and neurological biomarkers of the model organism Hediste diversicolor. The validation data indicate that this system can be used to assess independent or interactive effects of climate change and environmental contamination on benthic communities. Researchers will be able to simulate the effects of these stressors on processes driven by microbial communities, sediment and seawater chemistry and to evaluate potential consequences to sediment toxicity using model organisms such as Hediste diversicolor.