On Thu, 19 Apr 2001 Lee Bell <[log in to unmask]> wrote:

>Krazy Kiwi wrote:
>>Asian Mussel - AKA the Asian date mussel. We have this pest in our
>>Canning River, the Swan Estuary & the Fremantle area. It shares
>>many features of the Zebra mussel that has caused major damage
>>in North America.

>The jury is still out on the Zebra mussel.

I find "the jury is still out on the Zebra mussel" comment too simplistic
considering your country spends over $500 million each year in the Great
Lakes area cleaning pipes & water systems encrusted with the mussels.
Included in that cost is dealing with the litter problem (let alone the
smell) of decaying Zebra Mussels (ZMs) washed up on popular beaches during
storms.

>Recent reports suggest that this filter feeder is actually cleaning
>up badly poluted waters. While it's rare, this may be a case where
>a non native species has a positive effect.

Yes, ZMs can filter 1-2 litres of water per day with the benefit of better
viz - diver heaven :-)  But currently I see more negatives than positives
regarding this pest :-(

In San Diego the eelgrass beds may or may not benefit from ZMs.
Studies have shown if it is a HEALTHY & DENSE bed of eelgrass the ZM
starves to death.  Unfortunately, if the eelgrass beds are DEGRADED they
are overtaken & smothered by the ZMs.  The later is not good news for many
of the creatures that depend on that eelgrass for food & habitat (lobsters,
green turtle, shrimp, scallops, salmon, brant geese, etc).

In NZ it has displaced cockle beds in many harbours north of Auckland.
In our Swan River in Western OZ we are worried it will outgrow & smother
our main seagrass. In areas where the ZMs are so thick they look like huge
mats there has been a noticeable change in the sediments from sand to fine
mud. Our only saving grace is that between late autumn & early winter many
of the ZMs die off during our rainy season.

I suppose if it gets to plague proportions we could export it to China,
they eat it. I doubt it will ever appear on the seafood menu in this
country due to its small size. A couple of uses I hear it is good for is
fish bait, and as feed for shrimp & crab farms in Japan.
Viv