An Expanded Investigation into Aquaculture of the European Oyster Ostrea edulis

Primary tabs

Project Type: 
Research
Project Number: 
M/D-1208
Inception Date: 
2012
Completion Date: 
2013

Participants:

Larry Harris UNH - Department of Biological Sciences Principal Investigator
Proposal: 

The purpose of the letter is to request Sea Grant Development funds to initiate an expanded investigation into aquaculture of the European oyster Ostrea edulis. Ostrea edulis is becoming increasingly common in the coastal zone of New Hampshire, after being introduced as a candidate for aquaculture in Maine in the 1950s. Previous efforts in Maine have largely failed due to high mortalities from disease and physiological stress in upper estuarine environments. At the same time, the species is now established and increasing in coastal habitats. Very large individuals occur in our sea urchin aquaculture lease site in Little Harbor and they are very common in certain locations in Gosport Harbor at the Isles of Shoals. The intent is to incorporate O. edulis culture into an integrated multi-trophic system with sea urchins, bait worms, finfish and algae. The goal is to seek Sea Grant and other outside funding for expanded studies of European oysters, which are intended to expand aquaculture opportunities in the southwestern region of the Gulf of Maine.

I have collected over 200 oysters of varying sizes and have the larvae from a brooding female. The larvae are being fed an algal diet in attempt to settle them on shell fragments for growth studies. We also have several cage systems out in the urchin lease site with oyster shell fragments to investigate natural settlement. The purpose of this request is to seek funding to conduct field growth studies at two locations where adult oysters already occur and also to determine survival and growth of newly settled spat under different field and controlled conditions. I would like to deploy caged marked oysters of a range of sizes at both the urchin lease site and in Gosport Harbor at the Isles of Shoals and compare growth and survival through one year. We would also deploy more cages containing oyster shell fragments at sites in Portsmouth Harbor and the Isles of Shoals to compare natural settlement. In addition, we intend to compare growth and survival of newly settled oysters under a series of conditions, including cultures in recirculating systems fed commercial algal diets, free in an open tank system at the Coastal Marine Laboratory and deployed in cages at the lease site and the Isles of Shoals.

The planned studies would involve both graduate and undergraduate students in all phases of the research. I currently have two graduate students working on aquaculture studies supported by Hatch and College RAs and there are four undergraduates who have signed up to work on an integrated aquaculture system through the Ocean Projects course. In addition, four additional undergraduates are working in my laboratory assisting on aquaculture studies. The additional funding would allow us to greatly increase our efforts to incorporate European oysters into our laboratory and field studies of an integrated multi-trophic aquaculture system.

It appears to be a particularly opportune time to undertake these studies. Ostrea edulis has high market demand and is doing well in coastal environments and should make a positive addition to an integrated aquaculture system. Development support would greatly facilitate the initiative described in the preceding paragraphs.

2014 Accomplishments

N.H. Sea Grant researchers develop culture system to grow sea urchins and European oysters
Aquaculture is a growing industry in the Gulf of Maine, but so far efforts to cultivate European oysters and green sea urchins have not proven to be economically viable. With funding provided by a NHSG development grant, researchers worked to develop an integrated approach to raise these two species. In 2014, researchers developed a culture system to grow sea urchin larvae in the winter and European oyster larvae in the summer. This culture system will help to integrate these two species into the aquaculture efforts taking place in the Gulf of Maine for increased economic and employment opportunities.

NHSG research offers insight on recruitment and gear fouling for sea urchins and European oysters on underwater cages
Aquaculture efforts to raise European oysters and green sea urchins have thus far been met with limited success in the Gulf of Maine. With funding provided by a N.H. Sea Grant development grant, researchers conducted recruitment studies with both species deployed in cages for several months during the summer. Research results compiled in 2014 indicated that there was no difference in the number of oysters that settled in cages either with or without sea urchins present, although there was a significant reduction in the fouling of shells and cages when sea urchins were present. This research will help aquaculturists and resource managers to improve their techniques to raise European oysters and sea urchins in the Gulf of Maine for sale in local and global markets.

N.H. Sea Grant research indicates low mortality for sea urchins and European oysters raised in underwater cages
European oysters and green sea urchins have overlapping environmental requirements, but efforts to raise these species in cages have not proven successful in the Gulf of Maine. With funding provided by a NHSG development grant, researchers conducted recruitment studies with both species deployed in cages for several months during the summer. Research results compiled in 2014 indicated that the total number of oysters increased with the recruitment of juveniles and that mortality in the cages was low (10%). Survival of the urchins was 100% and cages with urchins were clean inside while cages without urchins were heavily fouled with algae. These data will help aquaculturists and resource managers to improve the success rate of raising both species for incorporation into new and existing aquaculture efforts in the Gulf of Maine.

NHSG researchers develop new caging system for bottom culture of European oysters and sea urchins
European oysters and green sea urchins are well-established in the N.H. coastal zone, but efforts to raise them via aquaculture have been a challenge. In 2014, N.H. Sea Grant-funded researchers developed and tested a caging system for bottom culture of European oysters and sea urchins. This cage system resulted in high urchin survival rates and allowed for urchin harvest without diving, thus enabling aquaculturists to improve their cultivation and harvest methods for both species in the Gulf of Maine.