Trophic levels of retained commercial catch

• Data sourced from DPI&F CFish database, catch per species (based on logbook reports for the four main fisheries: otter trawl, line combined, net and pot) was aggregated to broad trophic levels.
• It is important to note that there is very little information currently available on diet for most species retained in commercial fisheries from the Great Barrier Reef Marine Park.The trophic categories are therefore necessarily broad and the decision to include a species in a particular trophic level was based on best estimates for the adult dietary preferences of that species.
• It is noted that species can exhibit significant shifts in dietary preference as they develop through the various phases from juveniles to adults. In addition, there can be great plasticity in diet depending on the environmental circumstances.
• Understanding the ecosystem function of various species requires some information about trophic levels - this is a first attempt to do so and requires significantly more work.
• The majority of the catch is split between the top trophic level (e.g. species like coral trout and red throat emperors) and the bottom trophic level (e.g. species like prawns and crabs).
• It is clear that herbivorous fish are neither targeted nor retained except for a small quantity of juveniles taken by the Marine Aquarium Fish fishery (data not shown here). This is partly because of the combination of commercial fishing gear types allowed in the GBRMP (e.g. trawl, line, net and crab pot/dilly), partly because of the regulations surrounding what quantities of herbivorous fish species can be retained, and partly due to market preferences for predatory fish such as coral trout. Note that fish trapping is not permitted in the GBRMP and this is the major commercial method for targeting herbivorous reef fish in other coral reef ecosystems.
• The presence of large catches of higher order carnivorous fish is indicative of a relative healthy fish community in the Great Barrier Reef. There is no evidence that the Great Barrier Reef ecosystem has been subject to "fishing down the food chain" as described by Pauly (1998).
  

---

Citation and/or URL

Data for graph sourced from DPI&F CFish database. 

---

Spatial Coverage

Whole GBRMP 

---

Temporal Coverage

2007

---

Update Frequency

Continuous 

---

Other Information

See Fishing Catch from the Great Barrier Reef Marine Park

Pauly, D., Chrisatenson, V., Dalsgaard, J., Froese, R., and F. Torres Jr. (1998) "Fishing down Marine Food Webs", Science 6 Feb 1998 Vol 279 (5352) pp. 860-863.