Tide pools in Tobago

The best way to understand and love the ocean is to be in it. Anjani Ganase encourages youngsters, and their parents, to explore the sea, starting at the edges.

You do not have to be a swimmer to explore the ocean. Start on the beach, where the ocean meets the land, in the mangroves and at rocky intertidal pools.

Most beaches and bays of Tobago are lined by rocky shores with tidal rock pools to explore. My favourite and the most developed rocky pool system is Rocky Point in Mt Irvine. Here some rock pools are interconnected with deeper water channels that can be explored if you want to snorkel. In these rock pools, you are likely to find crabs scurrying over the rocks, barnacles, mussels, maybe tiny fish, an octopus and sometimes brain and finger corals, algae and sponges.

During low tide on calm days, I have explored the tide pools of Arnos Vale and Culloden. These pools are home to hermit crabs, tiny fish, and urchins. These are easy to get to when the tide is out and the sea is calm.

The ecology of tide pools is fascinating! Marine life in tide pools is adapted to extreme conditions. The organisms in these environments live a life of sudden and dramatic changes, one minute submerged by seawater the next exposed to the sunlight. It can be a harsh environment where – when the tide is out – there’s the risk of desiccation.

Tide pools show large fluctuations in temperature, salinity, oxygen concentrations and acid or alkaline levels.

Some organisms can move in and out of tide pools based for hunting. But these tiny pools can also serve as nurseries for fish and tiny invertebrate species. The timing for moving in and out of the tide pools is critical. Poor timing may result in being trapped or exposed. In some places such as Hawaii, where rocky shores are widespread and formed from lava flows, the tide pools are extensive and permanent. Many of the pools house great diversity, with unique, endemic species of crabs, mussels and other invertebrates. The tide pools of Hawaii are studied by marine scientists for insights into drivers of evolution and adaptation.

How to explore

Check the tide charts to choose the time to explore; when the tide is falling or low tide might be safest. As you become more experienced, you may want to see what is in the same pool at high tide; and what remains at low tide. Do not remove anything from the tidal pools and avoid stepping on the critters. You might want to wear secure booties to protect your feet. Use a mask or build an ocean-viewer or bathyscope using plastic.

A bathyscope is a tool that allows you to view underwater life from land. When you look at the surface of water, you may see only what’s reflected. The bathyscope works to allow you to look into the water by eliminating the glare on the water's surface. You are able to see as deep as the water's clarity and light permit.

Bathyscopes can be used to view life in rivers, the sea or other bodies of water. They are ideal for reef and tide pool viewing. Other devices that function like a bathyscope include glass-bottom boats, snorkelling goggles. Any transparent surface that can be submerged under the water's surface such as a glass bottle will allow you to see under the surface. However, glass may not be the safest material to use in your kit for a day at the beach.

Make your own ocean-viewer

Your ocean viewer can be made out of a plastic tube, bottle or a can. Attach to the end of the pipe a piece of clear plastic, cling wrap, Ziploc bag or a transparent plastic bag. Use rubber bands or duct tape to attach the plastic to the tube, and make sure the plastic is flat as possible with no creases. Dip the plastic covered end just below the surface to view underwater. Make sure water does not leak into the tube. Your home-made bathyscope is easily assembled for your beach days. Make it part of your equipment next time you hear, let’s go to the beach.