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Saving the Sea Cows! An Overview of the Manatee Crisis in the Indian River Lagoon

Natalie Clagett

Summary

  • Provides a brief introduction into why controlling nutrient run-off, algal blooms, and effects of climate change would improve Lagoon health and thus decrease manatee mortality.
  • Touches on federal, state, and local legislative and scientific efforts to conserve and grow seagrass coverage.
Saving the Sea Cows! An Overview of the Manatee Crisis in the Indian River Lagoon
mbell via Getty Images

One of the most biologically diverse estuaries in the world, the Indian River Lagoon (Lagoon) may have trouble retaining this title due to anthropogenic impacts and climate change. Florida Fish and Wildlife Conservation Commission, https://myfwc.com/wildlifehabitats/wildlife/manatee/ (last visited Nov. 22, 2021) (hereinafter FWC Website). The Lagoon currently displays symptoms of an ecosystem collapse, a collapse that would severely hinder the threatened Florida manatee’s survival. Id. Last winter, manatees died in record numbers from starvation due to a depletion in their main food source, seagrass. Id. This lack of seagrass is attributed to nutrient runoff into the lagoon, which causes seagrass die-off. Brian Lapointe et al., Evidence of Sewage-driven Eutrophication and Harmful Algal Blooms in Florida's Indian River Lagoon, 43 Harmful Algae 82–102 (2015). Over 950 manatees have died in 2021 thus far. FWC Website. In the Lagoon, 251 manatees died between January and May, which is roughly 37 percent of the total manatee deaths. See id. The deaths serve as a warning sign of an ecosystem on the verge of collapse. Id. This article provides a brief introduction into why controlling nutrient run-off, algal blooms, and effects of climate change would improve Lagoon health and thus decrease manatee mortality. Then, the article briefly touches on federal, state, and local legislative and scientific efforts to conserve and grow seagrass coverage.

The Fish and Wildlife Service (FWS) deemed the 2021 manatee deaths an unusual mortality event under the Marine Mammal Protection Act (which requires FWS to issue a contingency plan). 16 U.S.C.A. § 1421c (b)(1) (West). Biologists theorize that (1) the longer “winter,” beginning in December of 2020, prevented the manatees from venturing out of the Lagoon’s natural and man-made warm water havens as manatees must remain in water temperatures of about 20 degrees Celsius, and (2) seagrass has significantly decreased in the Lagoon. Zachary T. Sampson, Florida’s Deadly Manatee Crisis Could Flare Again this Winter, phys.org, https://phys.org/news/2021-08-florida-deadly-manatee-crisis-flare.html (last visited Nov. 22, 2021). Trapped in the warm water sites within the Lagoon with little to no food supply caused the manatees to starve to death waiting for warmer temperatures. FWC Website. Therefore, without increasing the seagrass coverage in the Lagoon through nutrient reduction and slowing the effects of climate change, the Lagoon’s manatee population will continue to decline. Although the manatee could also be uplisted from threatened to endangered under the Endangered Species Act, this would not provide additional protection as FWS already extends endangered species protections to threatened species such as the manatee, unless otherwise noted. 16 U.S.C.A. § 1538 (West). Because FWS has not made an exception for the manatee, endangered species protection extends to the manatee, therefore no benefit would be conferred from uplisting the species. 50 C.F.R. 223.

Nutrients, specifically nitrogen and phosphorus, fuel algal growth, which consequently reduces seagrass coverage. Lapointe et al., Evidence of Sewage-driven Eutrophication and Harmful Algal Blooms in Florida's Indian River Lagoon. Within the Lagoon’s basin lies roughly 140,000 septic tanks and a large agricultural region to the Southwest that seeps large amounts of nitrogen, phosphorus, and pesticides into the Lagoon. Michelle Snoberger, Cleaning the Indian River with Common Law, 34 J. Land Use & Envtl. L. 341, 345 (2019). Under the Clean Water Act (CWA), these nutrients are considered a nonpoint source pollution, which is a pollutant that cannot be traced back to a singular source such as a pipe discharging into the Lagoon. 33 U.S.C.A. § 1362 (West). The CWA does not prohibit or regulate nonpoint source pollution; however, it does provide funding and support for nonpoint source pollutants. 33 U.S.C.A. § 1329. These nonpoint source pollutants fuel harmful algal blooms, which release toxins into the water that stress wildlife and reduce light penetration to the seagrass beds, a necessary abiotic factor for seagrass growth. Lapointe et al., Evidence of Sewage-driven Eutrophication and Harmful Algal Blooms in Florida's Indian River Lagoon. Additionally, glyphosate, a common weed killer, has also been linked to fueling algal growth. Stephanie Seneff & Jennifer Margulis, Manatees are Starving in Florida. Pollution is the Likely Culprit Wash. Post, Apr. 5, 2021. Furthermore, the Lagoon’s inability to filter or flush nutrients quickly, referred to as a long residence time, compounds the excessive nutrient input, which allows the nutrients to accumulate in the Lagoon. Brian Lapointe et al., Nutrient Over-enrichment and Light Limitation of Seagrass Communities in the Indian River Lagoon, an Urbanized Subtropical Estuary, 699 Science of the Total Environment 134069 (2020). This accumulation provides a constant nutrient source for algal growth. Id.

Climate change also impacts the Lagoon’s manatees because of its long-term influence on seagrass viability. Holly Edwards, Potential Impacts of Climate Change on Warmwater Megafuana: the Florida Manatee Example, 121 Climate Change, 727–83 (2013). As sea levels rise, the Lagoon depth increases, which results in less sunlight penetration to the bottom that, like algal blooms, results in shrinking seagrass bed habitat. Id. Changes in weather patterns and increase in storm frequency and intensity also increases nutrient input. The storms increase underground seepage from septic tanks, sewage, debris, and add cold, dense water to the surface. Id. This cold, dense water contributes to stratification of the water column thereby reducing the oxygen on the bottom layer, creating a low to no oxygen environment, called hypoxic. Id. Algae thrive in hypoxic conditions and thereby further fueling algal growth and limiting seagrass coverage. Id. The storm events also directly impact seagrass because increased wave action and storm surge shifts the substrates, which increases turbidity and uproots the seagrass. Id.

The federal, state, and local governments have enacted laws and made financial contributions to the cleanup. In January 2021, the federal government enacted the Protect and Restore America's Estuaries Act, which provides additional funding to estuary cleanups, including the Lagoon. 16 U.S.C.A. § 1221. Additionally, the Coastal Zone Management Act requires states, like Florida, that have an approved coastal management plan, to incorporate nonpoint source pollution control into the state’s plan. 16 U.S.C.A. § 1455b. Florida delegates both point and nonpoint source pollution control to the five water management districts. Florida Coastal Management Program Guide at 31. The St. John’s River Water Management District orchestrates the Lagoon discharges, where the District’s primary abatement mechanism for nonpoint source pollution relies on plants to absorb nutrients before the nutrients can enter the Lagoon. Indian River Lagoon Surface Water Improvement and Management Plan at 5–15. The Indian River Lagoon Act, enacted in 1990, aimed to eliminate direct nutrient discharges into the Lagoon (including discharge from sewage plants) and to identify septic tanks and provide sewage access to those tanks to reduce seepage. Indian River Lagoon and Basin Act (1990). The latter of these requirements has yet to completely come to fruition as evident by the 140,000 current septic tanks in the basin. One county that surrounds a nutrient-dense area of the basin, Brevard County, has enacted ordinances that limit fertilizer usage during the summer, placed a 0.5 percent sales tax to pay for cleanup efforts, and now requires advanced treatment septic tanks within 197 feet of the Lagoon. Brevard County, www.brevardfl.gov/SaveOurLagoon/Home (last visited Nov. 22, 2021). 

The State of Florida limits Brevard County’s efforts to save the Lagoon through septic tank legislation and lack of funds. Current law requires local governments to give new septic permits to qualified residents, and therefore, Brevard County cannot enact an outright ban or these laws would be in conflict. West's F.S.A. § 381.0065. The Florida governor, on September 24, 2021, announced a $53 million grant to go toward cleanup efforts, specifically for septic tank removal or technology advances. Governor Ron Desantis, www.flgov.com/2021/09/24/ (last visited Nov. 22, 2021). However, to remove the nutrients, Florida will need to dredge the Lagoon. It is estimated that a 2015 dredging project represents about 5 to 10 percent of the total dredging needed, and it cost $10 million. From the Water: Healing the Indian River Lagoon, Florida Today Studios (May 1, 2020), www.youtube.com/watch?v=PDBik7mb3Mw. The state of Florida will need to increase their contribution efforts, and expand to more than just septic tank reduction, to save the Lagoon.

The federal government and state of Florida can take actions that would help not only the manatee but also the Lagoon. The State of Florida needs to (1) decrease nutrient runoff into the Lagoon, (2) extract current nitrogen and phosphorous to compensate for the lengthy residence time, and (3) work to reduce the local and global impacts of climate change. Scientists are attempting to clean up pollution through introducing natural nutrient filtration methods, like oysters and mangroves, and planting seagrass. When funds allow, manual efforts to remove nutrients through dredging should also occur. The efforts to save the manatees may be futile without financial and legislative support from the federal, state, and local governments. Scientists are hindered and mostly control the damage rather than the source of nutrient input. Without controlling the suspected sources, this Lagoon cannot heal and be the seagrass haven it once was.

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