Underwater Farms Off of Olhão
Updated: Aug 18, 2020
If you stood on the edge of the Ria Formosa estuary and looked out over the shallow water, mud flats, and small scraps of islands, you would have no idea of the intense beauty just below the waves. Seen from above, the clear waters paint the underwater topography in shades of aquamarine, teal, pthalo blue, pthalo green, and in the deeper areas, ultramarine blue. Solid organic matter - mud, silt, and plant life - add earthy notes to the spectrum, often tending from burnt umber to violet. It's as if a Creator looked around decided that they didn't need Roy, because G. Biv was doing just fine.
You will notice a white scale ruler on the left of the above image. That's one kilometer, to give a sense of, well, scale.
I can (and do) zoom around for hours here using Google Maps. I strongly encourage you to click on the header image for this article; it will open Google Maps with that view. Be careful, though - the salt pans are just to the north, offering big, bold colourful abstracts. An article devoted to them will be coming soon. Salt production is a fascinating industry with a history preceding ancient Rome. But I digress.
These images scratch a very deep artistic and creative itch for me. I have made my living as a scenic artist and painter for over twenty years, so manipulating colour and texture is basically what I do. Here is a post featuring some photos of my work for the theatre. When I do personal "canvas" painting (usually on a piece of 1/4" skin ply), I produce paintings that look very much like the images above and below. They are experiments in viscosity, diffusion, and flow using paints of different colours and consistency. Much spattering. For a while, I tried to reproduce coral atolls, aerial views depicting a small ring or patch of beach and vegetation, surrounded by underwater topography with this exact same palette.
I have deliberately not yet mentioned underwater farms, because I would like to reproduce the experience of finding them. In the above image, a section of Ilha do Coco, you will see some bits of dry land in the lower left. A beach, and some threads of land lined by the ubiquitous purple bushes. If we drop down a bit and centre the beach (that's 300 m wide across the curve, btw), we get the following view:
The first thing that catches your eye is the big "L" shape bottom mid-right. It looks a lot like a stylish Frankenstein boot. Let's zoom in on that a little...
Hm. Definitely not a natural formation, but also definitely underwater. Interesting. Looking northwest, just to the left of that beach - and notice there are two little buildings on that beach - we see more complex divisions:
This is clearly aquaculture of some kind, but what? Some Googling reveals that the Ria Formosa area is home to both mollusc and fish farming. I haven't looked into the fish farming yet, but the mollusc harvest consists of clams, razor clams, mussels, and oysters. That means that these artificially demarcated beds must be exposed at low tide so that they can be worked. That would be something to see. The mudscape looks so much like terrestrial fields and divided pasture lands as to be a little surreal. I keep expecting to see teal-tinted tractors pulling ploughs, little blue farmers hard at work, wee aqua villas:
Heading east a bit:
That's Ilha da Armona on the right in the above image. It's an interesting place worthy of it's own entry.
Feel free to wander among these underwater fields, stooping now and again to scoop up a bivalve or two. I'll be there.
"Algarve is the most important region for Portuguese aquaculture with the highest yearly production contributing with 4331 tons in 2008, which corresponds to 54% (table 1) of national aquaculture (INE, 2010). This region comprehends two distinctive zones: a smaller area – the Alvor estuary and the Ria Formosa lagunar system. Ria Formosa is the largest area devoted to aquaculture in Portugal and the most important wetland area in Portugal, comprising 750 ha of surface. This wide area is formed by a large system of canals and lagoons. Almost 90% of the total number of Portuguese farms is located in Algarve. The vast majority (96%) are concessions for extensive rearing of molluscs (Source: DGPA). Around 73% of the total volume of clams and oysters are produced in this region. The favourable ecological conditions allow a fast growth and favour the management and access to the molluscs’ production areas...
...Production of molluscs in intertidal areas is made in parks within their natural muddy/sandy substrate, located in areas protected from strong waves, and always under the influence of tides, allowing good water renewal. Most species are reared in monoculture systems due to different specificities. Farmers use the traditional knowledge together with some scientific support. In these systems the management is restricted to a skilful preparation of the soil, protection from predators, especially crabs, and algal removal. Technological inputs are restricted to some areas and include only mechanical harvest. Harvest is dependent on the tides and in some protected areas a knife is the only instrument allowed. In the spring tides, parks are exposed for harvesting during four to five hours, being possible to catch up to 15 kg of clams/person. On the other hand, during the neap tides, sometimes harvest is not even possible. In Ria Formosa the productivity has been dropping significantly. Before 1980, it was possible to catch between 20 to 50 kg of clams per person per tide. In 2005 harvesting values had already droped to 3 to 6 kg of clams per person per tide (Associação de Produtores em Aquacultura do Algarve – APAA – personal information). Although this decrease has been attributed to the presence of Perkinsus marinus a parasite which might causes high mortalities in the clams, the area has also suffered of large sewage impacts from anthropogenic sources which during the summer months had contribute to anoxia problems in the farming beds. In some sites mortality can reach 90%." (Portuguese aquaculture - The World Aquaculture Society, 20/03/2011)
Olhao Portugal aerial view.jpg by Toksave
It looks to me like the above image was taken at relatively low tide. Toksave has a few photos of Portugal in the Creative Commons. Here's one of theirs taken over Faro:
It's safe to assume these were taken minutes apart, so the tide is the same in both photos. The flats are really exposed, with the sea resembling rivers. Pretty cool.
I just noticed these structures built on the flats off of Faro. They are probably oyster or mussel beds/frames: