Increases in water precipitation and ocean acidification___consequences of climate change and CO2 emissions___affects the physiology and behavior of marine invertebrates. We postulated changes would occur in nervous system-controlled predator defense mechanisms, including bioluminescence, arm regeneration, and neuro-coordination abilities, such as the ability to return to upright after being flipped upside down. This hypothesis was tested by exposing the luminous brittlestar Amphipholis squamata (Echinodermata) to conditions of lower pH (pH 7.7, from pH 7.9), lower salinity (25 PSU, from 33 PSU), and lower pH and salinity combined. Exposure to the changes in experimental seawater chemistry for up to 7 weeks resulted in slower flipping times in the low salinity and in the low pH treatments and in high levels of leaking light in their bioluminescence response. These results indicated a negative effect on the neuro-muscular coordination and possibly the neuro-control of the light production. Brittlestar arms exposed to lower pH and salinity conditions experienced stunted regenerative growth, evidenced by shorter and narrower regenerative arm tips that were also less calcified. Brittlestars demonstrated difficulty expressing normal (control) predator defense functions following a 7-week exposure to low salinity conditions suggesting long term exposure resulted in prolonged effects on maintenance and repair mechanisms sustaining the brittlestar defense strategies. These data suggest compensatory energy reallocation toward maintaining normal function of other vital processes under stress. Quantifying the brittlestars behavioral and physiological responses can provide a clue for how their survivability will be impacted under projected low pH and low salinity conditions in the future.

The photoprotein of marine polychaete, Chaetopterus variopedatus, has been under investigation for decades because of its unique long-lasting light production ability and the potential of utilization in biochemical research as a reporter molecule. However, the exact light-producing mechanism remains unknown except that Fe2+ acts as the cofactor for the photoprotein. The goal of this thesis is to investigate this bioluminescence reaction pathway and to hopefully extract the previously unknown photoprotein. we discovered a preliminary relationship between

Fe2+ (photoprotein cofactor) concentration and mucus bioluminescence—a stimulation-inhibition dose response curve where ferrous iron stimulates light at a low concentration (£ 0.1 mM added) and starts to inhibit light as concentration increases (> 0.1 mM). Evidence suggests that Co2+ and Zn2+ are both competitive inhibitors for binding to the cofactor site on photoprotein and for bioluminescence. Co2+ has a stronger affinity than Fe2+ while Zn2+ has a lower affinity compared to Fe2+. We were able to purify Fe2+ binding protein from the mucus complex using Fe2+-affinity column. By using Co2+ as a substitute cofactor, we extracted from the mucus a light-inducing protein (37 kDa), which is a potential candidate for photoprotein or a protein that plays a role in the light production pathway.

The goal of this study is to describe the variation of metal concentrations in the environment of San Diego Bay, California, and assess the biological availability of metals throughout the Bay considering the local environmental characteristics. The concentrations of 15 metals were measured from sediment (top layer) and seawater particulates collected during an 8 week period from June 14 to August 9, 2001 at four sites in San Diego Bay, located near navigation buoys R8 (site A), R16A (site B), G1 (site C) and R34 (site D). Metals were also measured from tissues of the common brittlestar, Ophiothrix spiculata (Ophiuroidea, Echinodermata), transplanted from outside to inside the Bay. Experiments with transplants determined the ratio of metal from the environment that is biologically available to fauna. Measuring metal concentrations from disk and arm tissue of transplanted brittlestars determined the variation with time of metal contamination from the diet and/or from the seawater. Indeed, brittlestars can accumulate metals by feeding on metal contaminated food items that will mainly target the disk tissue, while they can also accumulate metals directly from seawater in arm tissue. The report also includes, from each site, environmental parameters such as surface and bottom temperature, salinity, turbidity and tidal height.

This paper describes some of the challenges of sustainability, and shows how they are manifested in coastal environments. It reviews the problems facing Venice and its lagoon, as a particularly interesting and complex example, and describes the technological, environmental, and scientific actions taken to address the problems of sustainability. Specifically, the actions and interdisciplinary research supporting management of the Venice lagoon environment are discussed, with a particular focus on the sediment. Conclusions are drawn regarding the integration of science, technology, and the environment, including the interactions of industry, the international scientific community, and governments.

Light producing proteins (photoproteins) are attractive molecules to study because of their potential applications in biotechnology and biomedicine. Photoproteins have been identified in several different phyla, however a photoprotein from the phylum Echinodermata has yet to be characterized. The goal in this work is to extract the calcium-dependent photoprotein from brittlestar Ophiopsila californica for purification and identification. The photoprotein was successfully extracted while maintaining activity. Three chromatographic techniques were used to separate the functional photoprotein from other constituents in the brittlestar extracts. The light producing fractions from each of these chromatography methods were analyzed using gel electrophoresis in attempt to identify a band that correlates with the amount of light production when comparing multiple fractions. A ~45 kDa band showed this positive correlation throughout each purification step. This band was characterized by ESI-QTOF-MS but did not result in the identification of a new photoprotein. Similar methods were attempted on isolated photocytes (light producing cells). However nearly all light producing activity was lost when attempting to extract the photoprotein from the cell. This indicated that the photoprotein relies on an intact membrane in order to function. This leads to the idea that the activation of this photoprotein could be different than the one previously proposed.

In order to understand the biogeochemical processes of involved in the relocation of dredged channel sediments in the Venice Lagoon, Italy, the SIOSED (Scripps Institution of Oceanography SEDiment research group) has carried out a research program from March 2005 to November 2007. Sediments were cored at various locations in the Venice Lagoon. In addition sediments were dredged from a navigation channel and transplanted directly into banks at two shallow sites. The monitoring program was essential since sediment in the Venice Lagoon is often contaminated with various metals and organic pollutants in different concentrations; consequently, most of the sediment in the lagoon has been evaluated as potentially hazardous. The sediment classification of the lagoon is organized into three categories based on the concentration range of various contaminants. Concentrations of the categories are based on total concentration values and on potential toxicity of each single contaminant; therefore, the occurrence of only one contaminant above the range characteristic of a specific category associates the sediment to the next more contaminated category. As part of this multi-disciplinary program, potential changes in the geochemistry of sediments were studied in relation to their dredging and reuse, including both the chemistry of solid phases and of interstitial fluids of the sediments. The present program of studies has emphasized the study of both major elements and trace metals in the sediments. Results of SIOSED sponsored studies on the distribution of Hg and the processes involving the generation of pollutants such as methyl-mercury have been already been published