I have added a bunch of new links to the Links Page. Although I really like the WordPress ‘Booklite‘ theme, it is not great for listing things so I have added the links to descriptive text instead. One of the new links is a flickr stream of beautiful macro photographs of Gastropods and Barnacles by Wales-based Morddyn (Ian Smith). Below one example of a very small species (that I discovered in my aquarium once), Cerithiopsis tubercularis:
Last weekend I took a little stroll on my local beach in Flushing and had a quick look at the variety of red seaweeds washed ashore. I saw some that I did not know, some that I knew, and some that I thought I knew….
I have recently joined the facebook group ‘Seaweeds of the NE Atlantic‘ and so immediately asked the experts for some help in identification. It turned out that the only one I correctly identified was the one on the bottom right: Solier’s red string weed Soliera chordalis. This (invasive) species did well in the aquarium and so did the one on the top right, which I always thought was Dudresnay’s whorled weed Dudresnaya verticillata but it isn’t! It is actually Chrysymenia wrightii, which is also an invasive species. Moreover, my ID of the bottom left species was also wrong: not Fine-veined crinkle weed Cryptopleura ramosa but Beautiful fan weed Callophyllis laciniata (I should have known this as I have found crinkle weed in France this year…). The small flat seaweed on top is Cock’s comb Plocamium cartilagineum. The dark mop top left could not be identified based on this picture so I have to go back to take a better one. So dear reader be warned and take my identification of seaweeds in previous posts with a grain of (sea)salt!
Two weekends ago I was back in The Netherlands for a short visit. The weather was great and we drove in my sisters camper van to the Brouwersdam, connecting the provinces of Zuid-Holland and Zeeland. This dam was built in 1971 and created the largest saltwater lake in Western Europe: the Grevelingen. We first stopped at the North Sea side of the dam though. This is spot is very popular with kite surfers, windsurfers and blokarters, with loads of people travel all the way from Germany even. Although great for sports, the Dutch coast is not the best place for a rock pool hunter (an bollenessor!) such as myself. The Brouwersdam provides hard substrate along an otherwise sandy coast, but there are no true rock pools and relatively few species of seaweed (mainly wracks and Ulva), some mussels and periwinkles and not much else:
However, this seaweed looked interesting (I also found it in Bretagne recently), but I just cannot get it identified, any suggestions?
*edit* commenter Edwin reckons Chordaria flagelliformis and this was indeed the page in my Seaweeds of Britain and Ireland where I lingered longest, I think he is right!
On the way back we stopped at the Grevelingen side. The Grevelingen is an unusual place: the water is salty, but there are no tides. There is only a very limited connection to the North Sea and so little water movement, which creates stratification and anoxic conditions in deeper waters, resulting in a ‘dead zone’. In shallower water there is plenty of life though (check this site for instance). We waded on mud through very clear water to have a quick look (mud is not stirred up by any current and the lack of any inflowing rivers keep the water relatively nutrient poor en algae-free) . There were many Shore crabs about, and they were quite aggressive, trying to pinch my toes:
I saw that Wireweed Sargassum muticum is very common here as well (see also this post and this post). These very large plants were colonized by fine red seaweeds and lots of Mysis shrimp were hiding underneath them:
I also stopped by the natural history museum in Rotterdam that I have been a member of over half of my life. I noticed that in their permanent ‘Biodiversity’ exhibition that there was a shelf dedicated to seaweeds. Of course they deserve a place in such an exhibit, but I must admit that they look a whole lot more interesting in the sea than dried or in alcohol/formalin.
In addition to animals, loads of different seaweed species could be found washed up on the beach in Pleneuf-Val-Andre:
Some of the species would look great in the aquarium I am sure. For instance Fine-veined crinkle weed Cryptopleura ramosa:Pestle weed Gigartina pistillata: (EDIT 2017: does not look like this species at all, be very suspiscious of my seaweed ID skills in older posts please!)Maybe a Plocamium species, I am not sure. I really like my Seasearch Guide to Seaweeds of Britain and Ireland, but it does not contain a key and I find it hard to determine some species based on a photograph.What would be great is to have a seaweed key app. I saw a great one this weekend for trees: leaf snap: take a picture of a leaf with your phone or tablet and it automatically gives you a list of best hits based on the outline (and perhaps colour, I don’t know), it worked really well. Seaweeds (actually pretty much all organisms) are too complex in shape, size and color for this. However, I could see an app working where the first screen would give you a number of pictograms, eg ‘dark encrusting reds’, ‘chalky reds’, ‘feathery reds’, ‘fan-shaped reds’ etc. After touching a first pictogram, new ones would appear, for instance to select the branching pattern, ‘irregular’, ‘whorled’, ‘opposite’ or ‘alternate’ and so on. Instead of such a purely dichotomous approach, it could also be possible to be presented with a wide variety of pictograms describing different properties (eg, colour, overall shape, texture, location on the shore), where it is possible to skip properties you are unsure about and still go ahead with the next steps. This would be a brilliant resource and help me identifying weeds such as this one:Anyway, a final seaweed (there were many, many more but this one I immediately recognized): Sugar Kelp Saccharina latissima. It is surrounded by various species of flat and tubular Sea Lettuce Ulva:
The weather was terrible last weekend so I only went for a brief trip to Flushing beach. It was noticeable that the Dumont’s tubular weed Dumontia contorta, abundant during the last months, is disappearing and flat red and green seaweeds are on the increase:
I found some Bushy Berry Wrack Cystoseira baccata (I think) and a very fine red seaweed that I could not identify using my Seasearch Guide to Seaweeds of Britain and Ireland:
An Estuary ragworm Hediste diversicolor:
My main aim was to get some finer sand to replace the coarse, white gravel collected from Maenporth beach that I have in my aquarium now. This sand is formed for a large part by remnants of Maerl, species of coralline algae. Beds of Maerl nodules are a threatened and important habitat for many animals and also other seaweeds.