The Snapper, the Groper and the Emperor – Donate Your Skeletons

By October 17th, 2013 at 3:15 pm | Comment

Drag your bones toward more Halloween-themed citizen science

Old Fish

The snapper, the groper and the emperor—these are not synonyms for that nasty blind date you landed last month, nor do they form the lineup for a cast of Halloween characters. These are fish. In particular they are demersal species, which refers to a type of fish that thrives in the briny depths, living and feeding at the bottom of the sea. Along with the West Australian dhufish and the bight redfish, the pink snapper, baldchin groper and redthroat emperor are being monitored by the Western Australia Department of Fisheries.

Citizen scientists can help with the project Send Us Your Skeletons. In particular a breed of citizen scientists who are invested in the future of their pastime can help—recreational fishers.

The Fisheries Department needs to know if significant management changes they put in place a few years ago are helping stocks to recover. They are asking fishers to donate the frames of fish caught by anglers, for research purposes. A fish frame is more than a skeleton. It is the fish without the fillets, or conversely, the skeleton, head and guts.

The department is currently collecting skeletons along the whole of the West Coast Bioregion (between Kalbarri and Augusta as shown by a map). “This is to ensure that the samples are temporally and spatially representative,” said team leader Dr. David Fairclough. “The current collection period is this fiscal year—July 2013 to June 2014. The samples for this period will be used in our next stock assessment.”.

The department records the length, sex and reproductive stage of the fish, and then removes the otolith or ear-bone. Examination of the otolith enables them to determine the age of the fish. When scientists gather a large number of ear-bones, they are also able to calculate what proportions of fish of different ages there are in a stock. Age structure is an important indication of the health of a population, and knowing the age structure helps fisheries managers understand if the current fishing levels are sustainable. The short of it is: donate your fish skeletons to ensure good fishing in the future.

The number of demersal fish frames from the WCB donated by recreational fishers in 2010/2011 increased from the previous year with twice as many fishers taking part; up from 179 to 352. This was an important result—it indicated a greater awareness of the monitoring program. Over the three years from 2008 to 2010, the fisheries department also collected 1,562 dhufish, 3,392 snapper and 995 baldchin from the commercial sector. The number of frames donated has provided comprehensive data upon which stock assessments can be calculated.

Tag

The first assessment back in 2007 identified declining stocks of these three species. Significant changes to the way the department manages the West Coast Demersal Scalefish Fishery were introduced to help stocks recover. Since then, their most important objective has been to monitor the indicator species for signs of recovery. To assess the status of their stocks, the Fisheries Department relies on the recreational and commercial sectors’ support in donating fish skeletons. The more frames collected in each zone of the bioregion, the more confident they can be about the status of demersal species stocks. Previous assessments showed that overfishing of the demersal species had been occurring.

“We have just completed the stock assessments for our three indicator species for the west coast demersal scalefish resource—West Australian dhufish, Snapper and Baldchin groper. These assessments were based on fish frames donated by recreational and commercial fishers between 2008/09 and 2010/11. The results of the assessment will be released shortly,” said Fairclough. The science reports will also be available.

Recreational fishers can now contribute not only to the science-based setting of catch limits, but also to the fishing future of their children. A big fish isn’t always an old fish, and an old fish isn’t always a big fish. Donate the frames and you will not only be entered to win a prize—either fishing gear or a courtesy charter fishing trip—but you will be contributing to management of both the big fish and the old fish.

The department is also monitoring pink snapper, bight redfish and blue morwong in the South Coast Bioregion, and the nearshore species—Australian herring, tailor and whiting in both bioregions.

Watch the video below to see just how to remove the fillets from your fish.

Helpful link:

http://www.fish.wa.gov.au/Documents/recreational_fishing/additional_fishing_information/send_us_your_skeletons_flyer.pdf

Image Credits:

Old Fish Table – West Coast Demersal Team, Western Australia Department of Fisheries
Tag – West Coast Demersal Team, Western Australia Department of Fisheries


Ian Vorster has a MS in Environmental Communications and most recently served as director of communications at the Woods Hole Research Center in Massachusetts. Prior to that he worked in the health communications field. Ian has served as a designer, writer, photographer, editor and project leader in the field of science, and now works freelance in a blend of these roles.