10.06.2019 – Sub-marina cleanup

For every single whale-watching tour, our boats cruise in and out of the marina in Calheta, a place that receives a substantial amount of tourists, particularly in summer, and is filled with fishing and recreational boats. After organising two cleanups this year, our team together with a handful of motivated free divers and volunteers, decided to go submarine and clean the murky waters of the marina. Despite this being a small cleanup, we all managed to remove a substantial amount of waste. The majority of the removed waste consisted of discarded fishing lines and metal waste as well as the usual perpetrator, plastic in all shapes and sizes. A lot of the trash was ridden with oil, underlining the worrisome level of contamination in the water.

Since marinas are man-made and ridden with boats, most people consider them a lost cause; a polluted soup, another anthropogenic mess. The reality is that the waters of the marina are a lot less disconnected than we think and just as cleanup-worthy as any other stretch of coastline on the island. Apart from the fish species that are typically expected in harbors, such as Mullets (Mugilidae) or Saddled Seabreams (Oblada melanura), we also saw a small pen shell (Pinnidae) stuck in the sediment, a relatively rare bivalve. We also had a few Fireworms (Hermodice carunculata) as well as a sea cucumber (Holothuria sanctorii) clinging to the waste. On other days, we also managed to locate very colourful organisms such as the common octopus (Octopus vulgaris), nudibranchs (Felimares picta) and crabs (Graspus graspus adscensionis) clinging to the rocks. Marine birds such as the Yellow-legged gull (Larus michahellis), the Yellow wagtail (Motacilla flava flava) and the Ruddy turnstone (Arenaria interpres) can also be seen in our marina.

While it is difficult to avoid oil contamination in an area with such a high density of boats, there are many simple changes that can be made to ensure that the fauna that can inhabit marinas will not disappear. Dumping any sort of waste in a marina just because it already assumed a polluted area is grievously unnecessary and damaging. After dutifully cleaning the muddy bottoms in the marina, our team took all volunteers for a whale-watching trip so that we all could appreciate one of the many reasons why such events are important for our oceans. We managed to locate a group of Short-beaked common dolphins (Delphinus delphis) that were already sighted this morning along with some rare Risso’s dolphins (Grampus griseus). What a day!

By Paula Thake

Sightings of the day

Ribeira Brava

13:30 Risso’s dolphins, Short-beaked common dolphins

17:00 Short-beaked common dolphins