2006/7 flood impact on Chek Jawa
Impact on Ecosystem
Ecosystem response
Long term effect
Foodweb crash
Salinity drop
Increasing abundance of tubeworms over time
Increasing abundance of invasive species: asian date mussels Musculista senhousia. These opportunistic creatures require big mortality events where there is low inter-species competition to facilitate successful invasion.
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Opportunistic invasive species: Recruitment of small sized organisms from neighbouring islands, which may compete with endemic species.
Changes in ranking with respect to abundance levels of species. Previously lower abundance species may dramatically increase and rank higher in terms of number.
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Producers recover in the long run
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Death of soft-bodied, non-burrowing animals: Carpet anemones e.g. Stichodactyla haddoni (directly affected animals from change in salinity: non-osmotic regulators/osmotic conformers)
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Loss of nutrient cycling
Loss of keystone species
Loss of habitats
Allowing primary consumers to recover, which in turn allows secondary consumers and tertiary consumers to increase in number
Loss of primary & secondary consumers due to die-off (may increase in primary producers due to fewer primary consumers)
Decrease in prey availability for tertiary consumers
Imbalance in food chains
Tubeworms are eaten by animals higher up in the food web
Could potentially bring back the secondary consumers that were originally lost
These mussel beds are able to dominate and exclude native species by aggregating in large numbers & can restrict the growth of seagrasses at the lagoon.
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However +ve points include providing additional habitats for other species such as snails to settle on.
Area covered by mussel beds peaked in Dec 2007, and declined in 2008. By Aug 2008, there were no more live mussels
replaced by other species like sea anemone and echinoderms
Another +ve point was being a source of food for sea stars, which could potentially bring back secondary consumers