The urgency of protecting coral reefs receives a great deal of media coverage, but did you realise that corals and jellyfish are very similar organisms? Jellies and corals are both cnidaria, but while corals stay put, attached to rocks where they grow and spread, jellyfish are only polyps in the early stages of their lives. After that stage of development, they bud off the rocks and float away.
One crucial thing they share with each other and with other marine life is their sensitivity to nitrates. Huge quantities of these salts, which are used as fertilliser in intensive pig and poultry farming, run off into the sea, and the latest chapter in this ecological disaster is unfolding on the north-western coast of France. Beaches including the famously glam Mont-Saint-Michel are being inundated with thousands of tons of sea lettuce (a common seaweed), which has being growing at an unnaturally rapid rate because of nitrates because of a process called eutrophication.
This isn't just disrupting the marine ecosystem, the heaps of sea lettuce are causing a deadly problem for us, too. As organic matter rots, it produces hydrogen sulphide, which gets trapped under the blanket of seaweed. This gas can have a devastating effect on the nervous system of animals and humans if a concentration of it is breathed in. The near-death experience of a horserider and council worker who were exposed to concentrated gusts of the gas are making the French beaches a no-go area.
What's the solution to the devastation wrought by nitrate fertillisers? Research into whether organic farming would reduce the amount of nitrate leaching into the seas hasn't provided an definite answer. One thing is for sure: if we don't move towards more environmentally-friendly farming practices, you might need more than a bucket and spade for your next day out at the beach. Does this gas mask match my bikini?
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Eutrophication is definitely a worry. Not sure that organic farming is necessarily the way forward, however; for one thing, they often use fertilisers themselves, but claim theirs don't count because they're 'natural'. Also, reduced yields of organic farms can result in either more land used for farming (reducing forestation etc. which provides a natural barrier to run-off water) or turning to other food sources... which can result in overfishing. Smart use of fertiliser, irrigation, water control and cleanup would be a more reliable all-round solution.
ReplyDeleteAlso, not sure I'm going to panic about organic hydrogen sulphide quite yet. Historically, I believe these are usually traced to undersea vents and similar. Is there conclusive evidence of the cause being organic in the incident mentioned in the post? Do you have a link?