The Wahle Lab







Wahle Lab                                                                                                      



Quick links to UMaine:

 Darling Marine Center

 School of Marine Sciences

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Nicole Messerman

Degree: B.S.

Institution:   University of Maine

Year completed:  in progress

Current Position: Student

Ocean Acidification and sperm motility in the Giant Sea Scallop
Placopecten Magellanicus


I am examining how ocean acidification affects sperm activity in the giant sea scallop (Placopectan megellanicus). My project is a spinoff of two projects under way at the Darling Marine Center: a NOAA project led by Richard Wahle studying scallop spawning and fertilization dynamics, and an NSF project led by Jeff Runge evaluating acidification effects on copepods. Since ocean acidification is becoming an increasingly relevant issue, it is important to try to understand how decreasing pH may affect sperm activity and fertilization success in these broadcast spawners. I ran multiple trials recording sperm activity overtime at various pH treatments and then I tracked the movement of the sperm using video analysis to calculate the speed of the individual sperm cells. I plan to continue this project after the REU program ends as my Senior Capstone Project at the University of Maine. So the next step of my project is to examine how decreasing pH affects the fertilization success in scallops. I am currently working on running fertilization experiments in the lab.




Ileana Freytes

Degree: B.S.

Institution:   University of Puerto Rico

Year completed:  in progress

Current Position: Student

Interoceanic comparison of predatory fish response to prey availability after habitat disturbance

   Ileana's REU project was a field investigation of the response of benthic and demersal fish to local sea bed disturbance that exposes small invertebrate prey, such as crabs and worms. Measuring the response of fish assemblages to local disturbance can be a useful indicator of local and regional differences in predation pressure.   Her project took advantage of the fact that during the summer her mentor, Dr. Rick Wahle (UMaine), was launching an NSF Rapid Response grant to investigate the impacts of the February 2010 tsunami on the benthic community of Robinson Crusoe Island, some 500 km off the coast of Chile in the southeast Pacific.  Ileana spent three weeks in Chile and the remainder of her REU in Maine, thereby creating the opportunity to compare and contrast two dramatically different marine ecosystems. Hailing from Puerto Rico herself, Ileana became a tremendous asset as an ambassador for the project.




Noah Oppenhiem

Degree: B.S.

Institution:   Reed College

Year completed:  2010

Current Position: Fisheries Observer, NMFS

In situ monitoring of tethered lobsters reveals diel shifts in predation intensity and cannibalism

   I used an infra-red illuminated, time-lapse, underwater video system to examine day-night differences in the level of predation on juvenile American lobster. Tethering trials were conducted at multiple shallow water locations in mid-coast Maine. Predation rates were surprisingly higher during the night than during the day. During the day most predators were crabs, but during the night virtually all the attacks were by larger lobsters that forage nocturnally.  To our knowledge, this is the first direct field evidence of cannibalism by the American lobster. Notwithstanding possible artifacts of tethering, these preliminary results suggest that cannibalism warrants further investigation as a possible mechanism of population regulation in lobster populations at high density. Lobster populations in coastal Maine are at historically high levels likely because of the depletion of predatory groundfish over the past few decades.