For the manatees, 2021 will tragically go down in history. The grim reality is that we have witnessed more manatee deaths this year than ever before on record. This crisis is indicative of an entire ecosystem breakdown and unless drastic changes are made, we fear that the situation will only get worse.
Thus far, efforts to rebuild the manatee’s population and prevent more senseless deaths have primarily focused on habitat restoration. It is a noble cause but may ultimately prove futile. Unfortunately, there is another threat to the manatees that few are aware of that could derail these efforts. Since the implementation of the IMO’s sulphur cap in 2020, an increasing number of ship owners have turned to open loop scrubbers to comply with the new regulations (they found a “loophole”- pun intended). Ships equipped with an open loop scrubber continue to use heavy sulphur fuel oil as the scrubber reduces sulphur oxide emissions from the ship’s exhaust. The byproduct created in this process though is a hot, acidic washwater containing, in varying concentrations, PAHs, particulate matter, nitrates, nitrites, and heavy metals including nickel, lead, copper and mercury (Boer & ‘t Hoen, 2015; Comer et al., 2020; Kjølholt, Aakre, Jürgensen, & Lauridsen, 2012; Teuchies, Cox, Van Itterbeeck, Meysman, & Blust, 2020). In most cases, this washwater is dumped directly into the waters that the ship is in (including next to or in the ports). The implications of this could be dire for fragile marine ecosystems. The components of scrubber washwater have been shown to cause bioaccumulation and eutrophication. This means that these chemicals could, at least in part, be causing the massive die-off of seagrass we are seeing and in turn leading to manatee starvation and death.
While more and more ships are using open loop scrubbers, regulations (and oversight) regarding scrubber washwater are lagging behind. Legislation on scrubber discharge in many places is completely nonexistent and in others severely inadequate. Washwater bans in ports can help but are often limited by size and enforceability. Even with the washwater ban in Port Canaveral, for example, it is likely that the manatees are still being exposed to scrubber discharges. Ships may stop using the scrubbers once in port but are certainly using them prior to that point. In fact, we wouldn’t be surprised if most ships only switch over once they are making their final approach to the dock. The sad reality is that no one is supervising these matters and ship owners have a long history of cutting corners with all sorts of other pollutants.
If we truly want to help the manatees, we need to address the threat of open loop scrubbers. While we recognize that this is a complex situation, impacted by many factors, open loop scrubbers pose yet another risk. As more ships rely on their use, things will only get worse. That is why we wanted to bring this issue to your attention. We are urging you to consider the implications of scrubber washwater in your work to restore manatee habitat. We are encouraging you to call for a wide-spread washwater ban and push for more regulations on open loop scrubber usage. This year’s record-breaking manatee deaths provide a painful reminder of how fragile marine ecosystems are. The fact is open loop scrubbers may be exacerbating the issue. If we don’t want to see history repeat itself with more record-breaking manatee deaths in 2022, we have to do everything we can to protect them.
News of this crisis has spread across the world. So many people are horrified by this tragedy and are desperate to help. As an environmental group, we, together with other likeminded organizations/persons have and will continue to elevate these issues across various platforms. It would be nice to be able to quote your response to the interested public.