Research Proposal: Caulerpa Prolifera

I have chosen to focus on an algae species known as Caulerpa Prolifera and its current invasion off the coast of Newport, California. There have been other Caulerpa species in the past that have invaded various parts of the world, including Caulerpa Taxifolia invading San Diego but was successfully eradicated in 2006 (NOAA, 2022). In order to eradicate the species, they ultimately ended up pumping chlorine into the local ecosystem specifically targeting the invasive species. Adding more chemicals to the ocean in general is a bad idea, but fortunately it didn’t appear to cause any drastic effects to the surrounding ecosystem this time around. Nonetheless, they tried other methods that didn’t work, including diver-assisted suction removal, which is the method currently proposed and in motion to eradicate Caulerpa Prolifera in Newport. There are a couple of issues with this: first of all, this species has the ability to reproduce through fragmentation, meaning it only needs a few millimeters of itself to grow and expand an entirely new plant in no time. This method relies on humans removing every single fragment of the plant and disposing of it properly away from the ocean. This is a difficult task because not only are we relying on there being no basic human errors in grabbing every little fragment of this algae, which are completely normal and expected, we are just assuming that the algae has not already spread elsewhere along the coast.

The point is, relying on human divers alone to eradicate this invasive species has historically been ineffective, how can we expect it to work now? With that said, it may still be a safer alternative for the surrounding environment to not pump toxic chemicals into the water, but is there really no other alternative? I propose a research project that takes place in a lab focusing on specific weaknesses of the species and if there are any predators attracted to it that could eradicate the invasive species itself, allowing nature to run its course.

We have already touched on the primary reason for this species’ invasive success being its ability to reproduce through fragmentation, even in minute amounts. It does have the ability to reproduce sexually as well when the opportunity is available. Another aspect that makes it so

difficult to eradicate, though, is its ability to thrive in many different types of conditions in the ocean. Caulerpa Prolifera can thrive in both sandy/muddy based conditions or on rocks/other hard surfaces. It has the ability to attach itself easily to a variety of surfaces and survive just fine. They also have the ability to survive in vastly different depths; they are typically found in shallower, brighter waters no more than 15 meters deep, but have been found thriving as deep as 50 meters below the surface. They have the ability to adapt to the changing light penetration but do appear different depending on their location: with higher light intensity, they tend to be more dense/compacted together, almost like a lawn on the ocean floor. In lower light intensities, they appear more thin and elongated, as if reaching for the light. Either way, an extremely versatile and dangerous invasive species.

Caulerpa Prolifera is native to the Mediterranean Sea as well as other tropical locations along the east coast of the Americas. It is a type of green algae, a chlorophyte seaweed belonging to the Ulvophyceae class of algae. While it does appear in nature on its own, it is commonly raised and sold for household aquariums as it’s easy to care for and attractive to look at. It’s believed that this species has popped up as an invasive species across the globe due to improperly disposing of the plant from these household aquariums. As previously mentioned, it doesn’t require much to grow and thrive, so this is entirely plausible. Other places this species has shown up as invasive include Portugal, the Canary Islands, and in the Suez Canal among others. Its invasiveness has caused the loss of other essential, local/native species historically, including eelgrass which is essential to the Southern California ecosystem as it functions as one of the bases of the local food chain.

Overall, the primary issue with Caulerpa Prolifera is how effective it is at choking out other vital, native species, and its stunning ability to be versatile in reproduction. This species is so successful due to its strength in surviving in multiple different environments and locations while spreading so rapidly and effectively. Anytime this species has shown up as an invasive algae historically, it has successfully eradicated or at least displaced many native species due to their inability to compete with the algae’s versatility. It has been able to spread all over the world in various locations thanks to basic human error and ample opportunity, making a name for itself nearly every time. If any Caulerpa species is not dealt with in a timely manner, including

Caulerpa Prolifera, it will take over the local ecosystem it has successfully infiltrated and cause catastrophic effects on the local food chain that relies on the native species this algae kills. It doesn’t seem as though one species of algae could cause such drastic effects, but this one is not to be underestimated and almost always requires human intervention in some capacity to ensure it does not continue to invade.

With all that said, I propose further research to be conducted in order to find a way to safely and effectively eradicate this species from locations that it will cause harm. According to NOAA, Caulerpa Prolifera in Newport is currently contained in one small area and they have not yet seen signs of it spreading elsewhere, as well as preventative measures have been implemented to attempt to keep it that way. It can spread rapidly and easily, so time is of the essence, but as previously mentioned relying on there being no human errors in removing this species thanks to its fragmentation abilities has historically been ineffective. At the same time, while historically effective, pumping the ecosystem full of chlorine can cause several other issues in the way of acidification or chemical imbalances in the water and should not be considered a solution unless absolutely necessary. I propose a project that would require samples of the algae be brought to a contained lab and experimented on in order to find what could be the algae’s weaknesses. This could include but not be limited to using alternative, safer chemicals, species that would specifically consume/prey on this algae that could safely be released into the local ecosystem or already exist there, or involving the use of technology in order to determine if the species is successfully eradicated and monitors for future invasions.

If it comes down to it, chlorine in solid form is what was able to eradicate another Caulerpa species in San Diego back in 2006, and was proven to not alter the chemical balance of the water. With that said, trace amounts of it still existed in the ecosystem that could be mistaken for food by another species, or prevent a native plant from being able to re-grow in that region specifically. With everything the ocean and its inhabitants are already facing today, adding more damaging chemicals in any capacity is doing more harm than good, even if in the short term it eradicates an invasive species. I truly believe there is a better, more natural way to control, eradicate, and prevent these invasive species from causing harm, and with your help, we could find it.

Sources

California Department of Fish and Wildlife. “Invasive Algae – Caulerpa Prolifera.”

CDFW, 2022, https://wildlife.ca.gov/Conservation/Invasives/Species/Caulerpa

Fisheries, NOAA. “Caulerpa Species on the West Coast.” NOAA, 25 Oct. 2022, https:// www.fisheries.noaa.gov/west-coast/habitat-conservation/caulerpa-species-west-coast.

Coastkeeper. “Caulerpa Prolifera Invasion.” Orange County Coastkeeper, 12 July 2022,

https://www.coastkeeper.org/caulerpa/.

Lamouroux, J.V. “Caulerpa Prolifera.” Subdiversion, 30 July 2022, https:// www.subdiversion.es/en/species/algae/chlorophytes/caulerpa-prolifera/.

Fama, Patrizia, et al. “Molecular Phylogeny of the Genus Caulerpa (Caulerpales, Chlorophyia ...” Repository, 2002, https://repository.si.edu/bitstream/handle/ 10088/6697/ Caulerpa.tufA.pdf?sequence=1.