Mangrove Kayak

Today I woke up on board ship to the lap of water on the hull. Outside the water was extremely blue despite some grey clouds but it was so hot and bright compared to Cumbria. We are going on a kayak tour of the Mangrove Lagoon at the tip of Beef Island guided by  Alex.
Mangroves are fascinating and vital parts of the global ecosystem. Protecting coastlines from wave and hurricane, stabilising silt run-off, nursery for fish, carbon sequester, and, together with coral reefs, influencing climate – so I was looking forward to seeing some pristine swamp!
It was not to be.
Alex took us out through some scrub land, where bright yellow mangrove warblers fluttered, to a small shingly beach where we launched the kayaks. 
The margin had a lot of yellow sea-weed washed up though, which we waded through.
Over the morning we wound our way through dense forests of mangrove, into lagoons and explored newly formed mangrove islands, each habitat having different dominant species of mangrove.
All was not well though. Where the lagoons should have been clear water, swarming with fish and other wildlife, vast amounts of  the yellow weed had washed in and settled covering the bottom, rotting, to take the oxygen from the water,
This was Sargasso weed – a free floating macro algae. The Sargasso sea in the Atlantic is one with no land borders. Instead, it has a complex of currents swirling around it to hold it in place. (It is famously the place where all the elvers go to grow and mature before coming back as eels to breed in rivers in the UK.)  Alex explained that with the rise in Atlantic sea temperatures the Sargasso weed was growing faster than normal . Also – and exacerbated by El Nino – the currents had changed and were not containing the weed. It was leaking out all over the Caribbean to smother shore lines. 
With previous severe hurricane damage, agricultural run-off, shore-side tourist and commercial development, mangroves and their treasure trove of diversity are under severe threat. 
 
Although it was a very bleak trip Alex managed to find a few places where the weed had not penetrated, and we saw wonders there. Upside-down jelly fish that deliberately upend themselves and lie, tentacles upright, on the shallow muddy bottom, every one slightly different in colour and configuration, one from another.
Mangrove crabs eyed us from the branches as we ducked into narrow waterways.
We came across a bunch of fern-like weed growing by the mangrove roots. Caulerpa Taxifolia – Amazingly each ‘leaf’ was a single celled organism. Later we saw Mermaid's wine glass Acetabularia crenulata, also single celled and looking like a fairy ring mushroom with the cap inverted. It seems that to organise shape and function these creatures have multiple nuclei within the cell. An alternative way of living!


In the afternoon we took a stroll along by the quay and had lunch overlooking an increasingly stormy sea and sky. As rain started to fall it was time to get back in the dinghy and retreat to the ship.