The reasons for the decline of the smalltooth sawfish (Pristis pectinata) population in the United States were mortality following capture in both commercial and recreational fisheries and habitat loss associated with coastal development and degradation. Following a listing of the U.S. population of smalltooth sawfish as “Endangered” under the Endangered Species Act (ESA) in 2003, NOAA Fisheries designated critical habitat for juveniles in 2009. But what exactly does that mean and what does that do?
Critical habitat is defined in the ESA 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. A critical habitat designation protects certain features, or attributes, of an area that are necessary to ensure the species does not go extinct and can recover to the point where protections of the ESA are no longer necessary.
When developing the critical habitat designation for smalltooth sawfish there was limited information about adult habitat use, so the focus was on those habitats used by small juveniles. Research determined that 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 were the features essential for the conservation of juvenile sawfish. 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. Research is ongoing to determine if there are habitats critical for large juvenile and adult smalltooth sawfish.
Two specific areas (units) located along the southwest coast of Florida were included in the critical habitat designation for juvenile smalltooth sawfish: the northern Charlotte Harbor Estuary Unit and the southern Ten Thousand Islands/Everglades Unit. 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 what that means. 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 7 of 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 of other activities, may propose actions that could affect critical habitat features. The designation ensures that the Federal Government considers the effects of its actions on critical habitat and avoids or alters 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 triggers a federal agency’s obligation to use their authorities to further the purposes of the ESA 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. The features designated for smalltooth sawfish are the basis of nursery habitat for small, young sawfish providing both shelter from predators and an abundant source of prey.
The critical habitat designation for smalltooth sawfish does not necessarily prevent a homeowner from building a dock or repairing a seawall, or 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. The designation of critical habitat for smalltooth sawfish in 2009 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 and beneficial to many other species.
For more information about the designation of critical habitat for smalltooth sawfish visit:
For more information about sawfish management and conservation visit www.SawfishRecovery.org.