Biodiveristy_State of Environment report - Mission Beach Cassowaries

ConditionThe AIMS conducts monitoring of reef fish throughout theGBR, but not specifically within the Innisfail sector. Reefwide fish biodiversity information is available on the AIMSwebsite at http://www.aims.gov.au/monmap/monmap.htm.A number of species of marine fish have been protected onthe GBR with no take policies and annual closures tofishing to protect fish during breeding seasons.ResponseThe rezoning of the GBR with additional protected areaswill assist in protecting marine diversity and fish stocks.CRC reef has demonstrated this in research work - theEffects of Line Fishing (ELF) experiment. The researchalso shows that reduced efforts by commercial fishing willbe even more effective, resulting in both better fishpopulations, and better harvests for fishers.ELF ExperimentThe Effects of Line Fishing (ELF) experiment, conductedby the CRC Reef Research Centre demonstrated thepotential effectiveness of the GBR rezoning over futureyears. The project was conducted on 24 reefs throughoutthe length of the reef, with some reefs normally closed tofishing being opened, and others normally open beingclosed. The results were as follows.“Analysis of information from the ELF Experiment up to2000 shows that reefs closed to fishing can have more andlarger coral trout and red throat emperor than reefs that areopen to fishing, with this pattern most obvious in areassouth of Townsville. There were rapid declines in fishnumbers on reefs opened to fishing, which stronglyindicated that without protection from fishing, these reefswould have fish populations that are similar to the openreefs around them. In contrast, the research found that fishstocks recovered following closure of reefs to fishing. Also,larger fish populations on closed reefs will most likely havegreater spawning capacity than those on surrounding openreefs. This adds support to the argument that green zonesare an effective conservation and fisheries managementtool.The research results also show that reducing the level offishing effort is the strategy most likely to seeimprovements in a number of indicators of fishery health(such as commercial catch rates and size of fish taken onreefs open to fishing). Effort restrictions and area closuresare required to achieve both conservation of fish andsatisfactory fishery performance leading to ecologicalsustainability.” (Reef CRC Website, 2005).Fishing effort describes how easy or difficult it is forcommercial fishers to catch fish. It is basically equivalentto how many hours a trawler would have to spend beforefilling the hold with catch. The ELF experiment shows thatthe current level of closures (~30%) will slightly reducefishermen's returns.But the interesting part of the research is that if commercialfishers started spending less time/effort fishing they wouldstart to make a better profit after only a year.This means that reducing the effort to catch fish results inthe fish population increasing, so that after a short amountof time, more fish are caught for the same amount offishing. The graphs in Figure 3.3.3 show projections forcatch per unit effort.Figure 3.3.3 - Modelling of Reef Closure and Fishing EffortSource: Reef CRC Website (2005)65