Friday, Nov 28, 2014
Columns

Indian River Lagoon provides cautionary tale on Manatees


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The U.S. Fish and Wildlife Service (FWS) is reviewing the status of the Florida manatee, a species that has been listed as endangered since the federal Endangered Species Act was created. The arguments heard to date to change the species’ classification to threatened seem centered around the number of sea cows that now swim in our waters. This is an over-simplification of a complex issue — something that happens all too often. We need only to look at our Indian River Lagoon to see the folly in this logic.

For decades, due to intense management efforts, not unlike those that have been undertaken for the manatee, seagrass acreages were increasing in the lagoon, and had reached pre-development levels by 2009. Seagrass growth and coverage was used as a proxy for lagoon health. Then came 2010, record cold temperatures, superblooms, and mass die-offs of that precious seagrass that had been doing so well.

Today we have an ecosystem in crisis; a lagoon that some fear may never recover. How could this happen? In retrospect, it appears that seagrass acreage may not have been the best metric for lagoon health, just as the current count of our manatees does nothing to indicate what dangers they face today, or could face in the future.

Over time, our lagoon faced repeated assaults from loss of salt marshes, to freshwater discharges that degraded shellfish habitat and carried excess nutrients into the lagoon, and wastewater and stormwater discharges that further contributed nutrient loads to the system. Periodic algae blooms indicated that something was awry, but not until 2011’s superbloom did we really come to realize the dire consequences of decades of nutrient loading into the Lagoon. Not only have these changes affected the lagoon itself, but also the many species who call it home, including manatees. Over 100 manatees have died of a mysterious ailment in Brevard County, believed to be related to the loss of seagrass, and the species need to utilize other, potentially toxic food resources.

As long as seagrass acreages were increasing, the Indian River Lagoon system was thought to be improving and the regulations on such things as septic tanks and stormwater discharges remained more lax than they should have. In other words, we were fiddling while Rome was burning, but we didn’t notice the fire.

We can’t afford to make the same mistake for our manatees, focusing on the species’ numbers and not on the current and future levels of threat the species faces from such challenges as climate change, sea level rise, Florida’s expected population growth, and the continued degradation of our water quality and water supply.

In 2013 we saw unsustainable record levels of mortality for the species, caused in large part by red tide and the mysterious ailment in the Indian River Lagoon. Manatees are living in a polluted environment. Until the root causes of that pollution are addressed and corrected, having more manatees than we had so many years ago simply means we have more to protect from an uncertain future.

Moving to remove manatees from the endangered species list now would be foolish.

Nathaniel Pryor Reed served as Assistant Secretary of the Interior for Fish and Wildlife and Parks (1971-77), has served seven governors, is best known as the highly visible Chairman of the Commission on Florida’s Environmental Future, and is a founding member of the Everglades Foundation and presently serves as vice chairman. Reed is the recipient of many national, state and environmental awards.

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