Starfish communication

Scientists have “cracked the code” of crown-of-thorns starfish communication.

For the first time, we are able to better understand the critical importance of the chemical communication that drives crown-of-thorns behaviour, providing excellent leads in the development of biocontrol technologies.

The paper ‘The crown-of-thorns starfish genome as a guide for biocontrol of this coral reef pest’ appeared online last month in the journal Nature. Click here to learn more:

No fish are off limits in Malaysia…

It’s 3:30am and pouring with rain but morale is running high. I’m at the fishing wharf in Kota Kinabalu, the capital of Sabah in East Malaysia. While many fishermen lay sprawled on soggy pieces of cardboard catching some much needed rest, others are still hard at work hauling crate after crate of their prize.

Malaysia Fish Markets Ocean Imaging

Malaysia Fish Markets Ocean Imaging

Malaysia Fish Markets Ocean Imaging
>To someone more familiar with the clean order of western fishmongers, the fish markets at Kota Kinabalu are a chaotic scene.

As the dimly-lit fishing vessels shuffled for space to unload their catch at the dock, I was struck by the huge volumes of seafood moving around me. There seemed to be fish from all families – many of which I was much more familiar seeing in the ocean than on the plate. Sure, there are a lot of people to feed and there is a genuine market for these fish, but I couldn’t help but wonder about the volume: how long can we sustain such intense fishing efforts?

Malaysia Fish Markets Ocean Imaging

Each crate was loaded with a specific species of marine animal. I looked at a crate filled with Unicornfish *Naso fageni*. In broken english, the fishermen happily remarked that they call this fish ‘chicken fish’. The local fisherman explained that the price fluctuates from day to day but would generally sell for between 15 – 20 Malaysian Ringgit per kilo ($5 – $7AUD/kg).

Malaysia Fish Markets Ocean Imaging

As crowds started to flood into the markets, fishermen shouted enthusiastically promoting their stands. Desirable fish such as tuna, dolphin fish, batfish or barracuda all sold for around 10 Ringgit per kilo, while the most sought after, Grouper and Spanish Mackerel could fetch upwards of 25 Ringgit per kilo. There were many stands covered in small reef fish such as Parrotfish, Surgeonfish and Soldierfish -for sale at just 3 Ringgit per Kilo (~$1/kg).

In one corner of the market, two young men sat sheltering themselves from the rain. On their table about among stingrays and guitarfish lay about a dozen juvenile scalloped hammerhead sharks (Sphyrna lewini). This was the first time I had seen this species which is listed as endangered on the IUCN Red List. In fact, despite having spent much time in the ocean over the last ten years, I’ve never seen any of the ten hammerhead species underwater. Sharks are arguably the most ecologically important species in the oceanic ecosystem. By feeding on weak, old and unhealthy fish, sharks stop the spreading of diseases among fish populations and control the intricate balance of our oceans food webs.

Malaysia Fish Markets Ocean Imaging

Malaysia Fish Markets Ocean Imaging

>The presence of juvenile sharks at the market had me shaken.

But it’s not just sharks that are under threat. All fish play important roles in the ocean food web. The small herbivorous reef fish which were especially abundant a the market, also play a crucial role in the functioning of coral reefs. By suppressing algal growth and scraping sediment, they help the corals to regrow. However the increased fishing pressure on these reef grazers has also contributed to the widespread loss of reef-building corals throughout the world^1.

Malaysia Fish Markets Ocean Imaging
>Various wrasse, fusiliers and even juvenile sweetlips were all for sale; fish of questionable palatability which rarely stray more than a few metres from their fragile coral reef homes.

At the market though observations at it seemed as the fish of highest ecological value were also the least desirable and profitable. Still, these fish were being caught and sold on a daily basis. For the local people of Sabah, this is normal. These are not bad people, they are just unaware of the ecological consequences of their fishing practices.

Malaysia Fish Markets Ocean Imaging

On my way back from the fish markets, out of curiosity I entered a dried seafood shop on the main road. Pick a local species of Seahorse or Pipefish, it was there in huge abundance. Later, I found more sharks at the local market in Tawau (the third largest city in Sabah) and even a portioned up Manta Ray. As a Marine Biologist and diver, I was shocked by what I saw.

Malaysia Fish Markets Ocean Imaging

Malaysia Fish Markets Ocean Imaging
>In Malaysia, there are no restrictions to which species are allowed to be caught and the amount of fish that is caught.

Malaysia Fish Markets Ocean Imaging

It is also common to see humphead wrasse (Cheilinus undulatus) on restaurant menus in Malaysia. These fish play a key part of the vitality of coral reef ecosystems as one of the few predators of toxic animals such as the crown-of-thorns starfish – coral eaters responsible for widespread, large-scale loss of coral reef habitat^2.

Malaysia Fish Markets Ocean Imaging

Overfishing is considered one of the most significant threats to coral reef ecosystems^3 but the answer is not a swift or simple one. The reality is, the majority of the 3 bn people who rely on the ocean for their protein also reside in areas where fishing activities have little or no regulation.

Malaysia FishMarkets Ocean Imaging

Managing only for the sustainability of individual species or target stocks of high value at the fish market is insufficient. When combined with spatial conservation measures such as marine protected areas, fisheries management can make significant contributions to ocean resilience and sustainable use. Locally, we should not neglect acting on issues such as these; we already have viable tools and a framework for achievable solutions.

The first step is to create international pressure to encourage governments to revise and intervene in exploitative fishing practices. There are also many other ways we can help too.

Malaysia FishMarkets Ocean Imaging

The economic influence of a fast-growing tourism industry holds the potential to catalyse this much needed change. In 2013, the total contribution of Travel & Tourism to Malaysian GDP was MYR $158.2bn (16.1% of Malaysian GDP^4, AUD $54.9bn).

As a world class diving destination, it makes sense that profits from diving and coastal resorts could be re-invested to sustain the reef communities they earn business from. Poor fishermen could be supported, to encourage more sustainable fishing practices, and benefit the future of local ocean resources rather than damaging them.

Malaysia FishMarkets Ocean Imaging

The time to act is now, lets see what we can do to increase the value of important marine species, habitats and ecosystems while we work towards a more sustainable way to feed the worlds growing population.

Malaysia Fish Markets Ocean Imaging

*This is the first post of a series discussing progress towards a sustainable future for the ocean in developing South-East Asia*

Coming Soon:
Education and Exposure to Marine Resources
Government Initiatives – MPA’s and Species Management
Future of Ocean-Derived Food – Sustainability and the Economics of Seafood

^1 – Burke L, et al. Reefs at risk revisited. World Resources Institute, 2011

^2 – Kayai, M, et al. Predator Crown-of-Thorns Starfish (Acanthaster planci) Outbreak, Mass Mortality of Corals, and Cascading Effects on Reef Fish and Benthic Communities, 2012

^3 – Roberts C, Effects of Fishing on the Ecosystem Structure of Coral Reefs, 2009.

^4 – Malaysia Economic Impact Report, 2014