Help spread the word!Share on FacebookTweet about this on TwitterShare on Google+Pin on PinterestEmail this to someonePrint this page

We were astonished and dismayed to read last week’s JEP story where Ministers were quoted saying there was nothing to be done about our burgeoning sea lettuce problem! Why the astonishment and dismay? Well,

Sea lettuce problems in Jersey - SOS Jersey are backing a potential solution!
Sea lettuce problems in Jersey – SOS Jersey are backing a potential solution!

with what we considered to be hopefully an elegant, ecologically sound and inexpensive solution, we had already approached various bodies on the matter.

This included bringing it to the attention of Minsiter Eddie Noel, John Rogers, and Deputy Richard Rondel during a meeting at TTS (Transport and Technical Services) HQ on 19 December 2014.

John Rogers (Chief Officer for TTS) certainly showed interest and we thought Eddie Noel (the Minister for  TTS) had too.

 

Potential solution to Jersey's sea lettuce problem, using native Jersey oysters
Potential solution to Jersey’s sea lettuce problem, using native Jersey oysters

Discouraged and slightly miffed, but not surprised and not bowed, by the complete lack of follow-up from States membersSOSJ and Tony Legg vowed to get the scheme going somehow.

As SOSJ has no funding we couldn’t help fund the scheme even for the relatively small amount it would cost.

We approached the JEP with the details and they have run our story (page 3, 26 August 2015), starring the brilliant Tony Legg who runs Jersey Sea farms. You can see the full article and letter on the JEP site here.

NOTE: One unexpected source of interest came last week and we’ll share details of this if it comes about. Nonetheless, we still believe this should be a States-funded and States-backed project.

The JEP also printed this accompanying letter (p10) from Dave Cabeldu, our SOSJ co-ordinator, which gives you the gist of what the oyster proposal is about:

SOS Jersey first proposed the idea of reintroducing the Jersey Native oyster (ostrea edulis) into St Aubin’s Bay a year ago. We had discussed it briefly with two Ministers who seemed very keen so we were surprised to hear that the COM had recently met and decided that there is no solution. We disagree.

We have researched the subject further and we believe that a solution could be less than three years away if a trial is undertaken now without further delay. There are no downsides or great costs involved,  and it would be an innovative and exciting ‘Jersey project’.

Studies we have seen show that the circulation of the waters in St Aubin’s Bay on most tides is just that – circular. Drogues released at the end of the Bellozanne outflow either ‘returned to base’, or went east into St. Clement’s Bay, so extending the Bellozanne outfall would not be the answer as often suggested. It would also be hugely expensive.

UK consultants last year went out looking for the ‘mother lode’ believing that it was possible that the lettuce was coming from elsewhere. This is not so. The  Ulva cells are present in the water column constantly.

As one sees in our reservoirs when an algae bloom occurs, the same principle applies to St Aubin’s Bay; a combination of slack tides, hot weather and high nitrates in the water will suddenly trigger the growth of the Ulva which is not washed away due to the circulation of the bay in normal summer conditions.

Therefore reducing the nitrate load in the bay by a relatively small amount should increase the ‘trigger point’ that sets off the process.

By growing juvenile Jersey Native oysters below low water level in self contained ‘micro reefs’, the nitrate load could reduce by 25% by year 3. The ‘native’ is very different to the Pacific oyster insofar that it not only takes up a lot of nitrates in its bulk, but also excretes biological products that are broken down in the sand by micro-organisms and turned into nitrogen gas which bubbles to the surface.

It is estimated that  just 125 tonnes of juvenile oysters would extract 35-40 tonnes of nitrates, or over 25%.

The oysters will be invisible below the low water line and can be commercially harvested so would be of economic benefit to the Island. If necessary they can be filtered in existing tanks as the Pacific oysters sometimes have to be. So there is no bacterial issue.

Add to that the measures being taken with the new UV plant that is scheduled to be fitted at the new sewerage works and measure to encourage farmers to use less phosphates on their land, a three pronged joined up sensible attack would be the way forward.

We ask the Ministers to rethink and authorise a trial without delay. There is nothing to lose and everything to gain.

 

Sea lettuce update – possible solution?
Tagged on:                         

Leave a Reply

Your email address will not be published. Required fields are marked *