Degree of Threat: Very high - high
Comments: Commercial bycatch played the primary role in the decline of this DPS. Quantitative data are limited but indicate that smalltooth sawfish have been taken by commercial fishermen and that this species has experienced severe declines in its abundance (NMFS 2003). Recreational harvest also may have had a significant impact (Simpfendorfer 2002) but is not now a significant threat (NMFS 2003).
Loss and degradation of habitat is judged to have impacted the distribution and abundance of smalltooth sawfish. The
continued urbanization of the southeastern coastal states has resulted in substantial loss of coastal habitat through such activities as agricultural and urban development, commercial activities, dredge and fill operations, boating, erosion, and diversions of freshwater run-off. Animal wastes and fertilizers from agricultural runoff contribute large amounts of non-point source nutrient loading and introduce a wide range of toxic chemicals into habitats important to smalltooth
sawfish. The rate of urban development in the southeast coastal zone is more than four times the national average,
destroying or degrading significant amounts of coastal and estuarine habitat. Commercial activities in the southeast eliminate or degrade substantial amounts of marine and estuarine fish habitat, although the exact amount is unknown. An analysis of 18 major southeastern estuaries recorded over 703 miles (1,131 km) of navigation channels and 9,844 miles (15,842 km) of shoreline modifications. Profound impacts to hydrological regimes have been produced in South Florida throughthe construction of a 1,400-mile (2,253- km) network of canals, levees, locks, and other water control structures that modulate freshwater flow from Lake Okeechobee, the Everglades, and other coastal areas. Potential detrimental impacts from the activities listed above on habitat of the U.S. DPS of smalltooth sawfish include: (1) loss of wetlands, (2) eutrophication, (3) point and non-point sources of pollution, (4) increased sedimentation and turbidity, and (5) hydrologic modifications. Smalltooth sawfish may be especially vulnerable to coastal habitat degradation due to their affinity for shallow, estuarine systems. The cumulative impacts from habitat degradation discussed above may
reduce habitat quality and limit habitat quantity available to the species. Given current low levels of abundance, and its
current retracted range, efforts need to be undertaken to better understand, avoid, minimize and mitigate these factors. [from NMFS 2003]
The scope, severity, and immediacy values refer to overexploitation (commercial bycatch) of the U.S. distinct population segment.