Author: Charlotte Young, Reef Ecology Lab Intern
Over the last century, plastic has become one of the most popular resources used worldwide for just about everything; packaging, manufacturing, clothing, cosmetics, even money. In fact, its global popularity means it’s become increasing difficult to avoid and as a consequence not only our lives but our oceans are drowning in it.
Plastic pollution is now considered one of the biggest threats facing our marine environment. And rightly so. Even our deep seas are plagued with plastic and its inhabitants added to the list of those species documented to have ingested it. Its sheer abundance means that wildlife readily come in to contact with plastic, even utilising it in things such as nest building.
Despite the doom and gloom, there are shimmers of hope. Here in the Red Sea we are considered one of the least plastic polluted regions with as little as 3,546 ± 8,154 plastic items km-2 documented in surface waters (Marti, et al. 2017). This is contributed to by the lack of freshwater inputs as Saudi has no natural rivers which are known to be significant sources of plastic transport to the ocean.
However, despite its relative low abundance, poor waste management in Saudi means that many of the beaches are littered with plastic, both macro and micro debris. Beaches are important intertidal habitats for a number of marine organisms, but in the Red Sea, beaches are of particular importance to one of the oceans most charismatic species, Sea Turtles.
Nesting on beaches during the summer months, eggs are incubated in the sand for a duration of 60 days and like other reptiles, it is the temperature of the sand which will determine the sex of the hatchlings. Variations in sand temperature are usual, however, high plastic content can change the thermal conditions of the sand and skew hatchling sex ratios to that of predominantly females (88 F for females, 82 F for males).
In a bid to understand how turtle populations in the Red Sea may be affected, Lyndsey, a former masters and now PhD candidate in the lab is on a mission to assess just how polluted turtle nesting sites are in this region.
To do this, Lydnsey, Kirsty (MSc Student looking at sand moisture in turtle nesting beaches) and I have to dig dummie nests, taking sand samples every 20 – 30 cm down to a total depth of 60 cm (the average depth of most turtle nests). This then gives us an idea how much plastic is in the sand, but also the proportions of debris at different depths.
Despite the alluring attraction of doing work with this species, the reality of the job is that it’s hard work! With daily temperatures reaching as high as 107°F during summer months, working conditions can be testing. But the importance of such work outweighs the tough days in the field as turtles are considered one of the most heavily impacted species by a number of different forms of plastic pollution (Wilcox, et al. 2016).
It’s not only plastic on beaches that poses a problem for turtles. During a recent fieldwork trip Lyndsey found a dead Hawksbill with some fishing line wrapped around its flipper. To understand what may have caused its death she took it back to the lab for stomach content analysis. What she found shocked us all. Over 5 m of fishing line was found in this animals stomach and gut. Completely in tacked, this poor creature had likely starved to death after eating such a large quantity of plastic which will have no doubt caused problems for it eating and digesting food.
Although shocking, this is not an isolated case. Turtles around the world are at high risk of plastic ingestion due to their normal feeding habits. Turtles will often mistake plastic bags for jellyfish, a normal prey source, and often become entangled in fishing gear which, as in this case, also has the potential to be ingested.
How this animal truly ended up with such a high volume of fishing line in its stomach we will never know, but as we move forward with our fight against plastic, it is important that each and every one of us takes responsibility for our use and appropriate disposal of our waste. As the tide on plastic is turning, more and more alternatives to are being made available. It’s important that as guardians of our oceans, we make these small changes, because it is collective action like this which can stop the plastic tap.