Smalltooth, Big Problems

Smalltooth Sawfish (Pristis pectinata)

By: Ryan Llamas

Smalltooth sawfish anatomy (http://members.optusnet.com.au/~alreadman/sawfish.htm)

ABOUT

Historical map range of smalltooth sawfish [FLMNH website]

Smalltooth sawfish, first identified in 1794, are one of two sawfish native to US waters (the other being the largetooth sawfish). They are considered part of the ray family but are also  related to sharks. The unique teeth-lined snout, typically ranging from 25-29 in number, of the sawfish is used in a side-to-side swinging motion to stun      or impale the small fish that it preys on and to dig for crustaceans along the ocean floor. Male smalltooth sawfish tend to have wider teeth while females’ teeth come to more of a point and like sharks, these teeth can fall out and be replaced with new ones. In general, the smalltooth sawfish live in shallow waters along coastal mangroves near river mouths. While its historical ranges ran along the Gulf of Mexico from Texas to Florida and even up the eastern coast of the US to North Carolina, today the population of smalltooth sawfish is reduced to the coasts of Florida. The worldwide historical ranges are not exact because many cases of misidentification have occurred between the smalltooth sawfish and other closely related sawfish but a few recent sightings place them in on every coast of Africa from Sierra Leon on the west, South Africa on the southern coast, and Madagascar to the west along with sightings in the Philippines and the north coast Australia. It is estimated that only about 5% of the population remains.

Endangered

            Smalltooth sawfish populations in the US were first listed as endangered on April 1, 2003 and as of Decmeber 12, 2014 the non-US populations were added to the list. The main reasons for the major reduction in population include:

Habitat destruction and degradation

Smalltooth sawfish in the Everglades National Park

http://sawfishconservationsociety.blogspot.com/2014/11/introducing-shark-population-assessment.html

-Smalltooth sawfish juveniles spend most of their time feeding in the coastal mangroves. Recent development of the coast of Florida has destroyed much of this habitat causing the population to be concentrated in the remaining patches.

      -Fertilizer and other chemicals are being washed                                                                                    down rivers in to the Gulf of Mexico and since smalltooth sawfish tend to live near the mouth of rivers they are heavily affected.

Bycatch

Smalltooth sawfish caught in a fisher’s net 

http://www.southfloridasharkclub.com/foro/viewtopic.php?f=37&t=2945

-Because of the shape of the smalltooth sawfish’ rostrum, getting caught in fishing net has become a major problem threatening this species. While guidelines have been established on how to release properly, for many it is too late.

Natural factors

-Smalltooth sawfish reach reproductive maturity late, have few offspring per pregnancy and have low growth rates so population growth is extremely slow. 

-Small initial population along with continued mortality due to habitat destruction and bycatch makes it very difficult to restore numbers to normal.


Recovery

Recovery zones  

[http://www.flmnh.ufl.edu/fish/sharks/sawfish/regional3.html]

The goals for recovery are to first change the listing of smalltooth sawfish from endangered to threatened and ultimately to be restore populations to a self-sustaining level and be taken off the list. This is to be done by minimizing human caused mortality, habitat restoration, and continual monitoring over the population. To be delisted 9 of the recovery zones including G, H, I, J, and K must have a juvenile population growing at 5% a year for 27 years or be over 80% of carrying capacity. In addition to reestablished population, state and federal programs must be in place to ensure bycatch and other causes of death are at a level that the species can maintain as well as produce guidelines for safe release if caught. Furthermore for the population to persist at least 95% of shoreline must be maintained and river conditions must be appropriate for breeding and overall survival. Lastly to be delisted the population must increase or maintain for 14 years following the down listing from endangered to threatened. Due to the slow population growth from the natural characteristics of the smalltooth sawfish, the process to recovery is predicted to take 4 generations, finishing in the year 2106 with a total cost of around $70 million.

http://news.caloosahatchee.org/newsletter/?page=prabhnewsletter_email_withoutform&id=103

For more information visit:

https://www.federalregister.gov/articles/2014/12/12/2014-29201/endangered-and-threatened-wildlife-and-plants-final-endangered-listing-of-five-species-of-sawfish

àDescription of all endangered sawfish species and the process off which each was classified as endangered along with their recovery plans

http://www.flmnh.ufl.edu/fish/Gallery/Descript/STSawfish/STSawfish.html

àThe Florida Museum of Natural History describes the smalltooth sawfish along with maps its historical and current world distribution

http://members.optusnet.com.au/~alreadman/sawfish.htm

àDescription of species along with picture of anatomy and ways the rostrum is used.

http://estuaries.noaa.gov/About/LearnMore.aspx?ID=456

àList reasons for endangerment along with characteristics that make recovery slow

http://ecos.fws.gov/docs/recovery_plan/smalltoothsawfish.pdf

àLists all requirements mandated for smalltooth sawfish to be down listed from endangered to threatened and then taken off the ESA list along with time and cost estimates.