by Tonya Wiley, Havenworth Coastal Conservation
Following a listing as “Endangered” under the Endangered Species Act (ESA) for the US population of smalltooth sawfish (Pristis pectinata) in 2003, NOAA Fisheries (NMFS) designated critical habitat for the species in 2009. But what exactly does that mean and what does that do?
The primary reason for the decline of the smalltooth sawfish population in the United States was mortality following capture in various commercial and recreational fisheries. The secondary reason for the decline was habitat loss largely associated with coastal development and degradation. So the preservation of habitat is an important consideration for conserving the species.
Photo Credit: Juan Valadez, Two juvenile smalltooth sawfish swim in very shallow water near a river mouth in Everglades National Park.
For the purpose of the ESA, critical habitat is defined as the specific areas within the geographical area occupied by the species at the time of listing, that contain physical or biological features (1) essential to conservation, and (2) which may require special management considerations or protection. The definition also includes a provision for specific areas outside the geographical area occupied by the species at the time of listing if the agency determines that the area itself is essential for conservation.
A critical habitat designation protects certain features, particular attributes, of an area that are necessary to ensure the species does not go extinct and can recover to the point that protections of the ESA are no longer necessary. For smalltooth sawfish the features determined to be essential to the conservation of the species are red mangroves and shallow, euryhaline habitats characterized by water depths between the Mean High Water line and 3 feet measured at Mean Lower Low Water. Euryhaline means the area can have a wide range of salt content, or salinity, due to tidal fluctuations and freshwater input as occurs in estuaries, bays, and lower reaches of rivers. These features were determined to be essential because they provide nursery habitat for small, young sawfish providing both shelter from predators and an abundant source of prey.
Photo credit: Tonya Wiley, Havenworth Coastal Conservation: A researcher prepares to release a juvenile smalltooth sawfish captured in shallow water along a mangrove shoreline in Florida Bay. Research conducted under ESA permit #1352.
Two specific areas (units) located along the southwest coast of peninsular Florida were included in the critical habitat designation for smalltooth sawfish: the northern Charlotte Harbor Estuary Unit and the southern Ten Thousand Islands/Everglades Unit.
Photo credit: NMFS Office of Protected Resources: The two units of designated smalltooth sawfish critical habitat.
So now that we’ve described why sawfish critical habitat was designated and defined both the areas and features of critical habitat, let’s look at how this affects coastal residents. How is the designation applied and what does it mean for coastal development or recreational activities? And how does the designation conserve the species?
The designation of critical habitat provides a significant regulatory protection—the requirement that Federal agencies ensure, in consultation with NOAA Fisheries under section 7of the ESA, that their actions are not likely to destroy or adversely modify critical habitat. The Federal Government, through its role in water management, flood control, regulation of resource extraction and other industries, Federal land management, and the funding, authorization, and implementation of a myriad other activities, may propose actions that are likely to affect critical habitat. The designation ensures that the Federal Government considers the effects of its actions on critical habitat and avoids or modifies those actions that are likely to destroy or adversely modify critical habitat.
Critical habitat can contribute to the conservation of endangered species in several ways. Designation under the ESA triggers a federal agency’s obligation to use their authorities to further the purposes of the Act which includes proactive conservation efforts. Designation also helps focus the conservation efforts of other partners, such as State and local governments, nongovernmental organizations, and individuals.
Photo credit: Dana M. Bethea, NOAA Fisheries: A neonate (newborn) smalltooth sawfish was captured and released on a muddy bank along a mangrove shoreline in Everglades National Park. Research conducted under ESA permit #1352.
The critical habitat designation for smalltooth sawfish does not necessarily prevent a homeowner from building a dock or repairing a seawall, result in new slow motor zones, close an area to fishing, or limit access to areas. What the designation does do is add levels of review to ensure that any project which could alter those essential features is carefully considered before federal permits are authorized or funds are allocated. In the case of smalltooth sawfish, critical habitat was designated in 2009 and has not resulted in any closed areas or lost recreational opportunities. But it has led to the protection of shallow, mangrove-lined habitats which are important to the recovery of the smalltooth sawfish population.
For more information about the designation of critical habitat for smalltooth sawfish visit: