deepseasgroup - pressure lab researchers

Name: Stephanie Price

Research project: The respiratory responses of Buccinum undatum to seawater pH and temperature changes predicted by 2100

Summary: Increases in anthropogenic CO2 and its subsequent uptake by the oceans has led to an average decrease in oceanic pH of 0.1 units since the industrial revolution in 1750 (IPCC Report, 2007). Climate change is also causing an increase in SST, with waters around the south-east UK coast predicted to increase ~0.15-0.4 °C per decade (MCCIP Report, 2007-2008). My research investigated the respiratory responses and survival of juveniles of the commercially important whelk Buccinum undatum (Linnaeus, 1758), local to Southampton Water, to seawater acidification and warming predicted by 2100. Juveniles were acclimated for 14 days to seawater maintained at one of three pHs and two temperatures through bubbling of CO2 into tanks of seawater contained in temperature-controlled water baths. At the end of the 14 day period, the respiratory responses of whelks were determined through measurements with oxygen micro-optodes and subsequent calculations of oxygen consumption. Survival of whelks from each temperature/pH combination was also noted at the end of this period. All pH and temperature conditions represented either the present environment in Southampton Water or predictions of warming and acidification by 2100. The combined effects of acidification and warming were examined to investigate how B. undatum will respond to climate-mediated stress within the next century.

Name: Felix Smith (Masters candidate)

Research project: The thermal response in a related hydrothermal vent (Mirocaris fortunata) and shallow water shrimp (Palaemonetes varians)

Summary: Molecular evidence indicates that vent bresiliid shrimp colonised hydrothermal vents in the Miocene, ~20 million years ago. Mirocaris fortunata is a hydrothermal vent shrimp found at seven sites along the Mid-Atlantic Ridge. In this highly dynamic environment organisms may be subjected to acute temperature changes as hot (350°C) vent fluid mixes with cool seawater (4°C). It has been suggested that extant deep-sea species originated through the radiation of shallow-water fauna. M. fortunata has been shown to be closely related to the shallow-water shrimp Palaemonetes varians which is found in brackish waters on the coast of Western Europe. Like their vent-living relatives these animals are subject to a fluctuating thermal environment, albeit not to the same extent as presented by the vent habitat. The close relationship between these two species makes comparison of their acute respiratory response to temperature shock relevant for understanding the adaptions required for life in the vent environment. The thermal preference of each species may also help explain why shrimp colonised hydrothermal vents rather than other deep-sea environments.

Name: James Morris (Masters candidate)

Research project: Growth and morphology in the Antarctic protobranch bivalve Yoldiella valettei (Lamy 1906); is there plasticity with depth and latitude?

Summary: Bivalves (Mollusca: Bivalvia), with their distinctive appearance are somewhat of a signature group within the phylum Mollusca and are among the best known and most easily identifiable of all invertebrates. This class is not only hugely important in economic terms encompassing commercially important shellfish, it also includes some of the world’s most endangered species (e.g. Pinna nobilis), as well as some vastly problematic invasive species (e.g. the Zebra mussel, Dreissena polymorpha). Ecologically, bivalves are vital components of nearly all marine and freshwater ecosystems. The subclass Protobranchia has one of the longest observed geological histories and its continuing success, particularly in deep and polar seas, is almost certainly due to a collection of physiological characteristics that enable it to survive in what are undoubtedly some of the world’s most rigorous and challenging environments.  Despite this, bivalve systematics lags behind that of other animal groups and our knowledge of certain groups within the class; particularly within the genus Yoldiella is virtually non-existent. This study focuses on the deep water protobranch bivalve Yoldiella valettei and aims to investigate potential plasticity (or presence of cryptic species) by comparing morphometric and growth data between populations from different depths, latitudes and other available physical parameters (sediment characteristics, degree of tranquillity, etc.). Morphological and growth adaptations that may be unearthed during this project e.g. body size alteration, extended growth periods, shell thinning and starvation resistance, will not only be able to be related to species within the same class but may also have polyphyletic applications.