Fishing Impacts
Florida Keys

hogfish swimming
Hogfish is a commonly targeted species for many spear and reef fisherman. Credit: FWC/NOAA

Why is it a concern?

Fishing is the most widespread exploitative activity in coastal ecosystems and poses significant threats to the biodiversity and condition of marine ecosystems. Although a recent study showed fishing pressure (i.e., number of trips, traps, angler days, etc.) in Florida Keys National Marine Sanctuary from both the commercial and recreational fisheries declined from 1995 to 2008, this decrease in pressure has an offsetting trend in that the growth in average fishing power (the proportion of stock removed per unit of fishing effort) may have quadrupled in recent decades. This increase results from technological advances in fishing tackle, hydroacoustics (depth finders and fish finders), navigation (charts and global positioning systems), communications, and vessel propulsion. Because of this, there remains a significant but largely undocumented effect of tens of thousands of recreational fishers who target hundreds of species using mostly hook-and-line and spear guns.

Threats from fishing are in the form of direct take, by-catch, indirect effects and habitat damage from the use and loss of fishing gear. The removal of non-target species (bycatch) may also result in cascading ecological effects. Fishing is also size selective, thus there are concerns about ecosystem disruption by removal of ecologically important key species such as top predators (e.g. groupers, sharks, snappers, and jacks) and their prey (e.g. shrimps and baitfish). Although additional, long term monitoring is necessary to adequately understand the impacts of new fishery regulations, initial research has shown that certain fish species (for example black and red groupers) have responded positively to the combination of stronger regulations and larger ecological reserve within the sanctuary.

Impacts from the trap fisheries include physical impact from fishing gear to marine habitats and introduction of marine debris. Regular yet unintended trap loss can result in trap ropes wrapping around coral heads and abrading or killing coral colonies. In addition, lobster or stone crab traps can continue "fishing" even after they have been lost, which leads to continued mortality of marine organisms that are too large to escape the traps after capture. Reef damage may also occur from anglers anchoring on reefs as well as gear impacts from lost fishing gear.

In addition to the traditional "hook and line" and trap fishing pressure, biodiversity in the sanctuary is also affected by the aquarium trade. In a study by Rhyne et al. (2009), the Florida Marine Life Fishery landing data from 1994 to 2007 was analyzed for all invertebrate species, and it was discovered that of the 9 million individuals collected in 2007 alone, 6 million were grazers. The results suggest the number of grazers greatly exceeds the number of other specimens collected for ornamental purposes, positioning the invertebrate ornamental fishery for a collapse. There is also a recreationally allowable "catch" of marine life, and there is currently no way to account for the level of effort or extraction this sector. More targeted research would help managers determine what effect both sectors of the marine life fishery are having on ecosystem biodiversity and integrity to help more effectively manage these resources. For example, there have been no stock assessments of any of the marine life species collected, thus it is impossible to determine whether this fishery is environmentally sustainable over the long term.

Overview of Research

Research conducted by Sanctuary scientists and partners provides critical information to address existing and emerging resource conservation and management issues. The Overview of Research highlights some, but not necessarily all, of the research activities completed or ongoing at the Sanctuary.

Project Name PI and contacts Links

Fore reef grouper utilize deep reef outside reserve

Florida Fish and Wildlife Conservation Commission

Large Spiny Lobsters are Migrating from Reserves

Florida Fish and Wildlife Conservation Commission

Science Needs and Questions

The best available science is used by Sanctuary scientists and managers working to address priority resource conservation and management issues. As priorities change and new issues emerge, each Sanctuary develops new science needs and questions and works with partners to address them.

  • Although not intended for fisheries management, how effective are SPAs and other FKNMS zones in the preservation of fin fish populations?
  • What are the effects of new artificial reefs, including the USS Hoyt Vandenberg, on local fish communities, and how do those effects cascade into the surrounding diversity of fish or habitat?

Education and Outreach Material

Please refer to the Florida Keys National Marine Sanctuary website to learn more about education and outreach materials.


Ault, J.S., S.G. Smith, J.A. Bohnsack. 2005a. Evaluation of average length as an indicator of exploitation status for the Florida coral-reef fish community. ICES J. Mar. Sci. 62:417-423.

Bohnsack, J.A. and J.S. Ault. 1996. Management strategies to conserve marine biodiversity. Oceanography 9(1):73-82. Electronic document available from:

Chiappone, M., H. Dienes, D.W. Swanson, S.L. Miller. 2005. Impacts of lost fishing gear on coral reef sessile invertebrates in the Florida Keys National Marine Sanctuary. Biological Conservation 121(2):221-230.

Cox, C. and J.H. Hunt. 2005. Change in size and abundance of Caribbean spiny lobsters Panulirus argus in a marine reserve in the Florida Keys National Marine Sanctuary, USA. Mar Ecol-Prog Ser 294:227-239.

Davis, G.E. 1977. Anchor damage to a coral reef on the coast of Florida. Biol. Conserv. 11(1)29- 34.

Frank, K.T., B. Petrie, J.S. Choi, W.C. Leggett. 2005. Trophic cascades in a formerly cod- dominated ecosystem. Science 308:1621–1623.

Mace, P.M. 1997. Developing and sustaining world fisheries resources: the state of the science and management. pp 98-102. In: D.A. Hancock, D.C. Smith, A. Grant, J.P. Beumer (eds.). Second World Fisheries Congress. CSIRO Publishing, Collingwood, Australia, pp. 98–102.

Office of National Marine Sanctuaries. 2008. Florida Keys National Marine Sanctuary Condition Report 2008. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Office of National Marine Sanctuaries, Silver Spring, MD. 42 pp.

Office of National Marine Sanctuaries. 2010. Florida Keys Science Needs, Dynamics of fin fish populations. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Office of National Marine Sanctuaries, Silver Spring, MD, Accessed: 7/22/2014

Rhyne A, Rotjan R, Bruckner A, Tlusty M. 2009. Crawling to collapse: ecologically unsound ornamental invertebrate fsheries. PLoS ONE 4(12):e8413.