The Potts lab studies a variety of question about marine environments.
Studies on an invasive mudsnail and its trematode parasites in the context of global change
The invasive estuarine mudsnail Batillaria attramentaria reached the western coast of North America as a passenger on Japanese oyster stocks in the late 1800s. It has established itself in estuarine habitats from British Columbia to Elkhorn Slough, California, where it reaches its greatest densities of up to 10,000 individuals/square meter. Batillaria displaces its native ecological analogue, Cerithidea californica in areas where it is introduced. Both snails are first intermediate hosts to trematode parasites, which utilize fish and birds as hosts in subsequent life stages. The Potts lab is investigating the environmental factors that influence parasite emergence in Batillaria, as well as the effects parasites have on snail hosts. They are also looking at Batillaria‘s role in cycling nutrients among sediment, water column, and algal pools in Elkhorn Slough, a highly anthropogenically impacted estuary that experiences moderate to hyper eutrophication seasonally. This work aims to shed light on ecological processes that are influenced by this invader, and to anticipate how these processes might shift as the physical environment continues to change.
Effects of ocean acidification on coral reefs: Field based studies
In collaboration with D. Adina Paytan (UCSC) and collaborators at the Centro de Investigación Cientifica de Yucatán, the Potts lab is utilizing a series of natural underwater springs on the Yucatán Peninsula of Quintana Too, Mexico, that seep low-pH ground water out over the reef. This natural laboratory permits the study of how coral reef organisms respond to low pH water and provides an opportunity to determine which species have the ability to acclimate and/or adapt to future pH levels. To date the work has focused on corals, forams and coralline algae.
Effects of ocean acidification on temperate marine invertebrates
The Potts lab is conducting laboratory experiments to determine effects of high CO2, low pH water representative of future ocean conditions (under acidification scenarios) on marine species local to Monterey Bay, with a focus on the growth, molting and survival of a local krill species, Euphausia pacifica.
Analysis of the sedimentology at Midway Atoll
The Potts lab encourages taking an interdisciplinary approach to its research questions. One such ongoing project is investigating the sedimentology of Midway Atoll – a latitudinally (28°15’N, 177°20’W) marginal reef theorized to be at the Darwin Point, the latitude beyond which erosion and subsidence exceed reef growth. High-energy wind and waves, plus circulation patterns altered by dredging, create a modified depositional setting. Regional and global effects of increasing atmospheric CO2 (e.g., altered wind and storm regimes, changes in stratification and upwelling), as well as local stressors, will challenge reef resilience. Past anthropogenic modifications provide dates for correlating stratigraphic horizons with identifiable reef responses over the last 10-200 years. Midway’s status as a National Wildlife Refuge and as part of Papahānaumokuākea Marine National Monument, along with its location in the North Pacific and anthropogenic record, makes it a model system for studying biological reef responses to environmental and human factors over a more geologically meaningful timescale.
Testing electrolytic technologies for biological reef restoration
The patented marine restoration technology Biorock® is an electrolytic process using weak DC electric currents to precipitate calcium carbonate on metal cathodes in seawater. It is also claimed to enhance settlement, survival, growth and reproduction of corals, oysters and other calcifying organisms, as well as non-calcareous species. The Potts lab is conducting the first laboratory experiments testing some of these apparent responses. They are also down-scaling the field technology to create a system in which can be controlled to quantify physical, chemical, and electrical as well as biological parameters, and document the responses of several living temperate and tropical species exposed to weak electric fields. If the claims are substantiated, this method has important potential applications for reef restoration, shoreline protection and mitigation of effects of ocean acidification.