Lake Biomanipulation

EAST POND Pilot BIOMANIPULATION Project

The ongoing East Pond bio-manipulation project is a pilot study and this first phase should be called a 'pre-implementation assessment' project. Given adequate funding, we plan on supporting consecutive graduate students over at least the next 4 year (2004-2007) period, during which the initial fish-plankton assessment work will be completed. The 'implementation (selected fish removal) phase' of the project will then commence in the spring-summer of 2006.

North and East Pond aerial photo

East Pond Restoration Project Update (2005). One-page summary about -- goal; problem of algae bloom; biomanipulation (fish removal) can be a solution; typical lake food chain; why lake biomanipulation; and ongoing project activities. You can help! Please report black bass tag numbers.

This is a cooperative project involving a number of groups including primary investigators - the Maine Department of Environmental Protection (DEP Lakes Assessment Section - Division of Environmental Assessment) and the University of Maine (Department of Biological Sciences). Maine DEP is working closely with the Maine Department of Inland Fisheries and Wildlife for technical assistance and fish collection permitting and the United States Environmental Protection Agency - in support of project funding. In order to qualify for EPA funding, considerable demonstrated work/progress has to have been made in the watershed to control nonpoint sources (NPS) of pollution. This is indeed the case for East Pond, where the Kennebec County Soil and Water Conservation District and the Belgrade Regional Conservation Alliance have received past Maine DEP issued grants and implemented watershed best management practices in recent years (2000 - 2003). We are also working in close cooperation with the East Pond Association and ongoing Colby College lake studies.

Notably, East Pond is just one of several lakes in Kennebec County that do not meet their water quality standards due to a combination of non-point source nutrients and altered fish assemblages - in terms of an excessive amounts of (1) phosphorus from soil disturbances in the watershed and (2) introduced white perch populations. Most folks do not realize that white perch - which are actually not 'perch' at all, but are in the same family as the striped bass - are only native to estuarine coastal waters, but have been historically introduced into many inland waters as a 'landlocked' sportfish. White perch do provide an important fishery in most waters where they occur, as they are usually very abundant and fairly easy to catch, particularly for angling novists and youngsters. The down-side is that they also tend to dominate the fish biomass - as evidenced in East Pond, where 90% of the fish abundance was found to be tied up in just this one introduced sportfish species - white perch, based on 2004 springtime trapnetting results only.

Following are some basic biological facts pertaining to lake biomanipulation:

(1) Project goal is to restore lake water quality (clarity) to help to revive summer
recreational opportunities and improve economic consequences for commercial
camps and shorefront property owners.
(2) Nuisance algae blooms are directly connected to in-lake phosphorus levels and
once total phosphorus reaches threshold levels, it is very difficult to reduce.
(3) Lakes have complex food webs and interactions between fish and zooplankton
can have direct effects on algal (phytoplankton) density.
(4) Manipulating the balance between resident biological species is called
biomanipulation. The stocking of sport fish is a common example.
(5) Reducing the biomass of the dominant fish species that consume zooplankton
may result in improved water clarity in impaired lakes.
(6) Manipulating the fish assemblage to improve water quality in East Pond, if
successful, has significant ramifications for other lakes in Maine with impaired
water clarity.

Biomanipulation Project Collaborators and Cooperators (primary contacts)

Maine DEP (Augusta - Dave Halliwell**, Melissa Evers, Roy Bouchard)
University of Maine (Dr. Katherine Webster, Tara Trinko, Dennis Anderson)
Maine DIFW (Region B - Bobby VanRiper, Bangor - Merry Gallagher)
East Pond Association (Jerry Tipper and Richard Seaman)
Colby College (Dr. Whitney King)
**Project Manager, Maine DEP, SHS #17, Augusta, ME 04333
207-287-7649, email: david.halliwell@maine.gov