March/April 1996
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March/April 1996 |
by Robert Kavetsky and Douglas Dodge
If you discovered you had lost your keys on a walk through a neighborhood at night, where would you start your search? Most people would look beneath the lampposts rather than feel along the unlit parts of the ground in between them. We acted similarly when we tackled the problems of trying to summarize the state of Great Lakes basin habitat types. Little is known about vast stretches of the basin, especially for some less common habitats. The Aquatic Habitat and Wetlands of Great Lakes background paper for the 1994 State of the Lakes Ecosystem Conference (SOLEC) snared data and expert opinion from far and wide to piece together this huge habitat puzzle.
Aquatic habitat loss and degradation is not well documented. Data that would shed light on the larger picture and its effects are almost nonexistent. Instead, there are numerous local studies split by watersheds, jurisdictions and disciplines. The assessment of the state of the habitats remains almost entirely anecdotal. Wetlands loss has been quoted as high as 8,100 hectares (20,000 acres) per year. This 1981 estimate was included in the background paper because it is the only guess that has been made, on a Great Lakes basinwide scale, of the magnitude of the ongoing net loss. However, the sheer number of anecdotes and their basic agreement allow only one conclusion: that habitat loss and degradation in the Great Lakes basin have been very high, especially in the highly productive and diverse inshore zone and connecting channels.
The different reporting methods behind the anecdotes point to a lack of "common currency" among jurisdictions, states, provinces and nations that was obvious from the background paper and discussion of it at SOLEC. Conference attendees stated that many local, state, provincial and federal regulatory programs, land acquisition, tax incentive and financial assistance programs are in place to protect and restore aquatic habitat resources. Strong authorities and laws exist in many jurisdictions to protect coastal wetlands, lakes and streams as well as inland wetlands. The authors could conclude from this argument that the rate of net loss has been substantially reduced. However the data upon which the original loss estimate was made are over 20 years old and no one has published a better one since. Identifying this data gap alone justified SOLEC.
A search of the 1992 and 1993 data of the U.S. and Canadian International Tracking System showed that 2,015 hectares (4,985 acres) had been restored and 2,380 hectares (5,875 acres) protected in U.S. counties that are at least partly in the Great Lakes basin. The total combined area for fiscal years 1992 and 1993 was therefore 4,395 hectares (10,860 acres). Comparing this to the previously quoted estimate of 20,000 acres lost per year basinwide, both countries appear to be falling well short of just keeping the wetland habitat base they have. Data on the extent and success of Canadian habitat restoration initiatives were not available at the writing of the SOLEC paper.
By and large, the open lakes are recovering from the eutrophication of the last decades. However, many species associated with them remain threatened because the inshore, shoreline and tributary habitats they also require have been lost or impaired. The dependence of the lakes and the species associated with them on healthy shoreline, inland and tributary habitats has been largely neglected. As a result, the impoverishment of these habitats has hardly registered as a Great Lakes issue.
Most habitat losses due to physical changes (e.g. filling, bulkheading, etc.) are mostly irreversible, while losses caused by biological and chemical changes have the potential to be reversed. Accordingly, it makes sense to focus on stopping the ongoing pattern of loss and impairment. Present losses are rarely the large-scale conversion of habitat to other uses; degradation is more common, in a variety of subtle guises that truly require an ecosystem approach to understand and reverse.
In recognition of the interrelated nature of living systems and their habitats, there is a growing realization by governments and their partner organizations of the need not only to protect the species that are in imminent danger of extinction, but to consider the entire picture and anticipate threats of extinction long before they become acute. To do this it is necessary to consider entire ecosystems, not just artificially separated fragments of them. Consideration of habitat is an essential component of this approach.
Clearly the health of habitat and wetlands is a major concern in the Great Lakes basin. A number of programs, laws and policies already exist to enhance habitats in the basin. What is needed to better protect and restore wetlands and other aquatic habitats is probably not more laws, but rather stronger will to conserve habitats, and implementation and enforcement of existing laws, regulations and policies. Coupled with this need for improved implementation and policy is the need for a strategic approach to habitat protection and restoration, making full use of all levels of partnerships.
The authors cochaired the Aquatic Habitat and Wetlands Committee of the 1994 State of the Lakes Ecosystem Conference. For more information, contact Robert Kavetsky, Great Lakes Biologist, U.S. Fish and Wildlife Service, East Lansing Field Office, 2651 Coolidge Road, East Lansing, MI 48823; Email R3ELFO@mail.fws.gov; telephone (517)351-5293; fax (517)351-1443; or Douglas Dodge, Great Lakes Branch, Ontario Ministry of Natural Resources, Box 5000, Maple ON L6A 1S9; email < a href="mailto:DODGEDO@epo.gov.on.ca"> DODGEDO@epo.gov.on.ca; telephone (905)832-7262; fax (905)832-7177.
To obtain the document described in this article, contact Robert Beltran, U.S. Environmental Protection Agency, Great Lakes National Program Office G-9J, 77 West Jackson Boulevard, Chicago, IL 60604 or Nancy Stadler-Salt, Environment Canada, Science and Integrated Programs Directorate, 867 Lakeshore Road, Burlington, ON L7R 4A6.
Sommaire
Dans le bassin des Grands Lacs, la destruction des milieux humides pourrait atteindre jusqu'à 8 100 hectares par année. Cette estimation, faite en 1981, constitue à ce jour la seule approximation concernant l'ampleur des pertes nettes dans le bassin. Toutefois, le nombre élevé de faits relevés et leur concordance ne mènent qu'à une seule et unique conclusion : la perte et la dégradation des habitats dans le bassin des Grands Lacs sont très intenses, surtout dans les zones diversifiées et très productives que sont les régions côtières et les voies interlacustres.
Des lois très strictes et des organismes de surveillance très actifs ont été établis dans plusieurs administrations pour protéger les milieux humides côtiers, les lacs et les cours d'eau, ainsi que les milieux humides de l'intérieur. Une analyse des données de 1992 et 1993, fournies par le système canado-américain de surveillance, révèle que 2 015 hectares avaient été réhabilités et 2 380 protégés dans des comtés américains situés au moins en partie dans le bassin des Grands Lacs. En comparant ces données aux 20 000 acres perdus chaque année dans le bassin, on s'aperçoit que les deux pays ont encore fort à faire pour simplement maintenir la superficie actuelle d'habitats de milieux humides.
La protection et la réhabilitation des milieux humides et des autres habitats aquatiques ne nécessitent pas l'adoption de lois additionnelles, mais se fondent plutôt sur une volonté accrue de conserver les habitats et sur la mise en oeuvre des lois, règlements et politiques existants. À ce besoin d'améliorer la mise en oeuvre et les politiques s'ajoute la nécessité d'élaborer une approche stratégique pour protéger et restaurer les habitats, en faisant appel à tous les niveaux de partenariat.
Revised: 28 February 1997
Maintained by Kevin McGunagle,
mcgunaglek@ijc.wincom.net