The Dutch part of the North Sea is predominantly sandy or muddy and its benthic life consists of animal species adapted to these sediments. Life on and around shipwrecks shows a strong contrast because it is made up of species preferring hard substratum. Consequently, wreck fauna adds significantly to the total biodiversity. Moreover, it contains several higher taxa such as sponges, hydroids, sea anemones, bryozoans and nudibranchs, which are hardly represented on sandy and muddy substrates. Also the fish community seems to be enriched as we encounter high numbers of fish like Gadoids swimming close to wrecks, a phenomenon well known to the sport-fishing community. Not surprisingly, wrecks have been compared to ‘oases in a desert’.
However, wrecks are considered artificial substrates and as such do not gain much protection in frameworks such as the European Habitat Directive, which often focus on more ‘natural’ communities. We may ask ourselves whether this is correct: next to the added value in terms of biodiversity, the biological communities of wrecks and other hard-substrate objects such as oil rigs resemble communities that have been present in the past such as oyster banks and exposed peat (‘moorlog’). These substrata have almost disappeared during the last century probably due to anthropogenic activities.
What is the ecological relevance of life on and around shipwrecks in your country?
Dear Godfried. In Portugal, especially in the Azores, artificial reefs either shipwrecks or others, are divided into two main groups: archaeological parks and artificial wrecks. Both are monitored also for biodiversity and ecological successions and atract an increased interest from both the scientific community and tourism operators. In my personal oppinion and experience I generally favour artificial reefs and structures especially when over sandy/muddy bottoms since they give us a chance to accompany ecological successions as in no other way they can be done. Presently, I've almost completed a paper dealing with the biodiversity associated to Azorean marinas and a another one dealing with a similar study that I did with co-authors in an offshore oil platform off S Brazil is accepted. Please find attached the 'popular' version of the latter (sorry its in Portuguese).
I totally disagree with the "political correct"m somehow electoralist and turned towards non-professional, albeit eventually well intentioned, ONG's that press politicians towards a false idea of something "pristine" while forgeting that underwater environments are full of extraordinary biodiversity sites based on wrecks and artificial reefs (e.g. Austrália, Mediterranean, Caribbean, etc...).
The EU Habitat Directive is getting, in my oppinion more and more politicized and less scientific. I'm affraid they pay much more attention to some kind of "surrealistic Garden of Eden" than to biology and ecology in particular.
Many thanks for your important and extremely usefull question and further discussion in this fórum.
Best regards,
JP
Article Plataformas de petróleo – Pontos de encontro de peixes em alto-mar
Hi
I live in Mauritius where we have many shipwrecks that were sunk specifically to make artificial reefs. Many of them are popular diving sites as they have attracted a lot of fish. To my knowledge there has not been any monitoring of these wreck looking at how successful they have been. The latest ship (an old fishing boat) was sunk last year, 2014, on a sandy bottom and divers have already reported seeing shoals of fish.
Personally I have nothing against sinking ships to create artificial substrates especial around small islands like Mauritius where the reefs are under a lot of pressure. Human activities as well as climate change are having a lot of negative impacts on our Reef. So much so that coral farming as well as other methods of transplanting corals onto artificial reef systems are being looked into.
With increasing human impacts, artificial substrate are a very attractive solution to increasing resilience and hopefully preserving the reef . To answer your question, life on and around wreck is extremely appreciated in Mauritius and has been for several decades.
Best Regards,
Natalie
Please ask Rob Leewis in the Netherlands, he knows a lot about hard substrate species
Hi Franciscus
Rob Leewis is among my co-authors and one of my followers. Moreover we share the same home-country, the Netherlands, and I am especially interested in reactions from abroad. How about Germany😉 ?
Dear Godfried
Last November in Papua New Guinea (Irian Jaya side) I made some exceptional dives on wrecks from WWII. Amazing and totally understudied while some even uncharted and not explored. More recently (Zaire river January 2016) I spearfishes for specimens of several predatory fish and tagged crocs in a very difficult área filled with shipwrecks and many other artificial reefs. If you like I'll make a list of áreas and surely will be very glad to welcome you as co-author for the upcoming papers.
Please note my e-mail ([email protected])
Best regards,
JP