Practical Fishkeeping Feature

When it pours it rains: another feature in print! A while back, I was contacted by Chris Sergeant who had a plan to write a piece for Practical Fishkeeping Magazine on rockpool inhabitants, to be accompanied by a short interview with me about my native tank. As coldwater marine tanks represent less than 1% of all aquaria this would be a nice ‘niche’ article that could introduce this part of the hobby to other aquarists. The issue arrived at my doorstep today, and as the blog name is mentioned, I thought I’d better write a quick aquarium post!

I have not been posting much about my aquarium lately (click on the ‘aquarium update‘ tag at the bottom of the page to see relevant older posts). This is in part because the aquarium on the whole has been ticking along nicely and in part because covid meant I have not been diving or visiting different beaches much this last year and so have not introduced many new inhabitants. There are a few changes though: in the photo above you can see a mermaid’s purse of a bull huss (or nursehound) shark that my son found washed ashore, tendrils tied to a suction cup. The gestation period is up to 11 months, so let’s see what happens! I have also reintroduced prawns, as they are active and really pretty when you look up close. I have also added a scallop, but need to relase it sometime soon as it is not able to filterfeed properly. The bit of kelp tied to the pump has been surviving (it would go too far to say thriving) for quite some months now. Although the beadlet anemones have spawned quite a few offspring, I am going through a phase where many are wasting away. I have no idea if this might be a disease or if this batch of anemones has just reached the end of their natural lifespan.

I have posted a bunch of tank pics below. For more info on my tank please have a look at the July issue of Practical Fishkeeping (which also features reminiscences on rockpooling by editor Nathan Hill). I promise to post more regularly about the tank here on the blog though, and also on instagram. Please also see the Links page for other relevant blogs and websites. Anyway, I am very honoured to appear in ‘PFK’; a true institution when it comes to the aquarium hobby in the UK!

Back in the Water

I had not been in the water for many weeks due to bad weather, work and laziness, but as the sun was shining last Tuesday and there were indications from social media that the plankton bloom had gone, I went back in for a snorkel. The water has warmed up, although the viz was not as good as I had hoped. I swam a bit further than my usual shallow rockpools to explore the kelp forest. Pollack, wrasse, mullet and sandeels swam about. I noticed a line with crabpots starting very close to shore, something I had not seen before. Unlucky spider crabs and some lobsters could be seen in the pots. Below a Spider Crab that was still free….

After exploring the slightly deeper waters I went back into the pools where the viz actually cleared up a bit. Seaweed-wise, things have deteriorated a bit compared to early spring, but it was a very nice swim around all the same!

Natural Aquarium

A quick posts of some wide angle photos I took at the start of this month. The seaweeds were just past their prime but still looked nice and the viz was really good. It was great to slowly swim through the water in my usual spot between the rockpools ‘proper’ and the kelp forest. Just like swimming in a giant aquarium! Not too many fish or other animals to be seen. I always manage to suprise one big resident Ballan Wrasse. Other than that there were tiny Pollack and some Two-Spot Gobies. I have not been in the water since because the weather (wind) has not been great; maybe next week! Btw, I am also on instagram: @an_bollenessor.

Rockpooling on St. Martins

Although St. Martins does not seem to have any rockpools, the beach that was nearest to us (called ‘Lawrences’) has a stretch of rocks lying on the sand that can be turned over at low tide, and so we did! A nice find was a small Sevenarmed Starfish Luidia ciliaris (these can grow up to half a meter across, although you will not find them that size in rockpools). We also found a Bootlace Worm Lineus longissimus, which is (probably) the longest animal on the planet. These nermertean worms secrete a powerful toxin in their mucus, but luckily for us it affects arthropods and not mammals. They are not very rare btw, I see them here in Flushing and Falmouth too. It was about 5 meters long (without stretching it), but they can grow ten times the size of this! In the second photo you can see it in its natural habitat, under a rock, with some photobombing crabs and worm pipefish. Another cool find was a juvenile Conger Eel Conger conger. Otherwise we found the usual suspects, lots of crabs and a bunch of fish, see for a small selection below.

Back on St. Martins, Isles of Scilly.

Last week we visited St. Martin, one of the Isles of Scilly again, the first week we were allowed to do so. As a result, the islands were very quiet (and the pub was still closed, aargh!). It was sunny, but the easterlies were still cold and there was even a bit of frost some nights. However, I managed to get a snorkel in almost every day, which was great. I brought all my gear (again stepping on the boat wearing my weight belt…) but only used the strobes the first day; these are still an ongoing frustration of mine! I tried out most beaches, especially enjoying Porth Morran, where the kelp met the seagrass. (The pics in the Gallery are click-able btw.)

Some sites were dominated by kelp Laminaria digitata with Common Sea Urchins Echinus esculentus munching away. Fish life was very limited; I saw Ballan- and Corkwing Wrasse and Thicklipped Mullet but not much else.

Common Sea Urchin Echinus esculentus

Other sites were more ‘beachy’ with white sand, small rocks covered in Snakelocks Anemones and Seaweeds and Seagrass. The visibility looked very promising but was quite bad some days unfortunately (especially compared to our visit last September, see here). All in all a great time was had and we hope to visit again next year!

Seaweed Assemblages

I have been trying to make the most of the seaweed season the past few weeks. This mainly entails lying motionless in two feet of 9C water, taking 100s of pics until my finger refuses to press the shutter lever. It is a lot of fun! Yesterday was a no go unfortunately: the easterlies picked up (there were even surfers in the water which is very rare at Gylly Beach) and the water was very milky. I managed to go a few times last week though and here are some photos of seaweed assemblages with names (there are a few species hidden that I did not bother with, so these do not fully do justice to the biodiversity).

Red and Green

Just a very quick post: went for a snorkel today as the sun was shining; there was some wind so the viz was not the best. Snapped a lot of ‘6’s but I liked the green Ulva lactuca (sea lettuce) and the red Sphaerococcus coronopifolius (berry wart cress). Both are plants (‘Plantae’) and not related to the brown kelp in the background (which is more closely related to potato blight!).

Rockpooling in Flushing

The wind has picked up and will ruin any chances of getting good seaweed shots this week. Too bad, but what can you do? A bit of rockpooling I guess. I took my son out to our local beach in Flushing where the rocks gently slope into Penryn River. Although there are no ‘proper’ rockpools, low tide gives access to a mixture of maerl sand and rocks that can be turned over. It is silty and definitely not very pretty, but there is always something to find. It was an especially good weekend for finding fish, seeing Shannies, Tompot blennies, Rock gobies, Gunnels, Worm Pipefish, Shore Rocklings and a tiny Eel, as well as Sea Scorpion eggs. (One Shanny was quite big and proceeded to bite my son’s hand; he was very brave and we slowly put it back.)

Invertebrates were plentiful too. The main mollusc here is the Variegated Scallop Chlamys varia, which is attached underneath every single rock. We found our smallest Great Scallop Pecten maximus as well. We found some Sea lemons Archidoris pseudoargus and lots of Yellow-plumed Sea slugs Berthella plumula (which apparently can secrete sulphuric acid when disturbed…). A small selection of what we found below, all pics taken with an Iphone.

An Bollenessor is Back

It has been a wile since I last posted. This winter was long and dreary, the sea choppy and grey. I managed to do some rock pooling, and took a bunch of pictures, which I probably should have posted… The good news is that a mishap with my camera housing last year resulted in Olympus giving me a new model housing + a new model camera to fit (OMD EM1 mark 2) AND a new dome, lucky me! Regular readers of this blog know I get very excited in March, as this is when the seaweeds look at their best. This week the tides were low and the wind conditions favourable (the sun was not always out unfortunately), so I made sure to go in the water every day. The water is cold (9C), especially after being in for 2 hours, but it is all worth it. The seaweed growth was lush, with species literally growing on top of each other. I tried to shoot with strobes, but this proved too difficult and switched to natural light. Keeping ISO at 200, I aimed to lower shutter speed to 1/30, managing an F stop of between 5 and 8, depending on cloud cover. I now get the hang of that, but it is difficult to keep photos well-exposed, with enough depth of field and maintain sharpness. Below some examples. I am lazy and will not add seaweed names (but see the Seaweed Gallery page at the top if you are interested). When the tides are low again at the end of next week I hope to go out again!