Tanzania and Kenya throwback – when I went exploring on the beach

It is almost four months since I returned from my expedition to Tanzania and Kenya… I definitely miss being there in the sun (and having to drink six – eight litres of water every day!)

Our first camp was near the city of Tanga and was situated right on the coast – we were pretty much camping on the beach. Every morning as I ate my breakfast I would sit in awe watching the sun rise over the Indian Ocean, and days working in the village often ended with a swim in the sea.

dsc_0181

One day we were given the afternoon off to relax, so while the tide was out I went for a walk with my camera. The beach was teeming with life and I had a fantastic time observing and photographing it.

dsc_0106

The beach was surrounded by mangroves which when the tide came in became submerged. Their roots are incredible structures – they grow like this to maximise oxygen absorption (the roots need oxygen but there is very little in the sand).

dsc_0108

dsc_0109

There were also these huge structures that at first glance just looked like rocks – it turned out that they were ancient coral reefs that had died and formed little islands of their own.

dsc_0161

Below are a few photos of interesting creatures/shells that I found on the beach…

Giant clam shell

dsc_0111

Interesting seashells (despite much searching, I have been unable to identify these)

dsc_0158

dsc_0160

Crabs (also very difficult to identify! The red-brown one may be a rock crab, but I’m not entirely sure)

dsc_0114

dsc_0177

Brittle star

dsc_0125

When I first came across the creature pictured below on the beach, I was completely mystified. It seemed like a strange shell structure sunk into the sand, but it was unlike anything I had ever seen before. However, recently when I was learning about the evolution of eyes as part of my zoology course, I saw a picture of it in an article that I was reading.

dsc_0163

It is the West Indian fuzzy chiton… the thing that surprised me the most is that the shell actually contains many tiny mineral eyes! This bizarre creature has eyes made of aragonite – the same material used for the rest of its body. The images produced will not be of the greatest quality, but they are enough for the chiton to be able to detect predators and respond by clamping themselves into the sand.

I cannot believe I was lucky enough to see such an incredible creature on my travels.

Advertisements

Work experience with the National Trust – rivers

Last weekend I left the city for a day to participate in a work experience event run by the National Trust. It was the first of six days which will be spread over the next few months, offered to students studying biological science related subjects at the University of Manchester.

The sessions are held at Quarry Bank Mill, Cheshire, and are based around conservation work that takes place there – the first one was focused on the river Bollin, which runs through the estate.

dsc_0003-6

In the morning we were taken to the weir to see the work being done to protect fish species – the weir is almost seventeen foot high so creates an impassable barrier for migrating fish (for example salmon) which would be trying to swim upstream to breed.

This has resulted in a loss of salmon from this section of the river, as they would no longer be able to breed there (the water further downstream is not oxygenated enough for young fish to survive).

dsc_0002-3

For this reason, a fish pass was installed – this runs next to the river and enables fish to bypass the weir and swim upstream. There are two channels: the first was simply a wide tunnel (allowing fish to swim through), whereas the second one had a ‘substrate mat’ – this gives eels something to wind around so that they can also move up the river. The mat was placed on a slant in the water so no matter what the depth, any size of eel could swim through.

There was a submerged camera looking into the fish pass, enabling National Trust rangers to monitor which species pass through. The camera is activated by movement, so a lot of the time the images obtained are of debris being carried downstream. However, this year for the first time, they have footage of a salmon moving upstream. This is fantastic news as it shows that the fish pass is working, and that hopefully salmon will begin to breed in the river Bollin again.

The picture below shows the fish pass: it was a bit difficult to photograph due to the metal grill over the top, but the right hand side is for the eels (you can see the slanted substrate mat) and the left hand side is for other fish. The red light source is there to aid the camera at night – fish cannot see red light so this does not disturb them. The camera is in the wall on the far left, behind a plastic screen.

dsc_0007-4

In the afternoon we walked to a different point on the river and collected data such as the river width, depth and flow rate. Monitoring these factors allows rangers to keep track of any significant changes in the river ecosystem, so that their conservation efforts can be more effective. Unfortunately I didn’t manage to get any photos of this part of the day as I left my camera in the truck (we were wading into the river so I didn’t want it to get damaged – not to mention the fact that by this point my fingers were numb!)

Hopefully this has given a little insight into the conservation of rivers – my next session with the National Trust is at the end of January so I will write another blog post about it then.