Red Tide
-
We are planning to grow Asparagopsis Taxiformis seaweed in the Philippines(PI). This is for cattle to reduce methane. But the Philippines has a lot of Red Tide outbreaks making shellfish not eatable. So we intend to grow mussels and perhaps oysters to reduce nutrient levels. PI has 7000 islands and 200,000 people growing seaweed but still imports mussels. The three products gives us staggered harvest times which has a lot of benefits.
@dennis_barron - Heres a link to recent scientific study that is very relevant to your situation and your aquaculture plans with bivalves and seaweeds in the face of red tides: Mitigation of harmful algal blooms caused by Alexandrium catenella and reduction in saxitoxin accumulation in bivalves using cultivable seaweeds - ScienceDirect
In this study, the researchers showed that three different species of seaweeds (Saccharina latissima (sugar kelp), Chondrus crispus (Irish moss), and Ulva spp.) were capable of reducing concentrations of the red tide algal cell Alexandrium catenella by causing the red tide cells to burst open (cell lysis), presumably through allelochemicals released by the seaweeds. Not only that, but when sugar kelp was co-cultivated with blue mussels (Mytilus edulis) in the presence of red tide cells, the sugar kelp significantly lessened saxitoxin (STX) accumulation in the mussels , keeping levels (71.80±1.98 µg STX 100 g−1) below US closure limits (80 µg STX 100 g−1) compared to mussels grown without sugar kelp present (93.47±8.11 µg STX 100 g−1).
Overall, the study suggests that the co-cultivation of seaweeds and bivalves "represents an environmentally friendly and potentially profit-generating measure to mitigate A.catenella-caused damage to the shellfish aquaculture and harvesting industries." The seaweed species you plan to grow was not tested in this study, so I can't say for sure if it will provide protection to your bivalves from red tides. But there is also a growing body of evidence that the co-cultivation of seaweeds and bivalves can also be beneficial to bivalve growth as photosynthesis by the seaweeds helps to raise the pH in the localized waters around the seaweed, providing a halo of protection from ocean acidification to bivalves co-cultivated in close proximity. Here's a link to a very recent study that I co-authored that demonstrates this: Frontiers | Kelp (Saccharina latissima) Mitigates Coastal Ocean Acidification and Increases the Growth of North Atlantic Bivalves in Lab Experiments and on an Oyster Farm | Marine Science (frontiersin.org)
So overall the science is showing many benefits to co-cultivating bivalves with seaweeds that can help make aquaculture businesses more profitable and diversified, and I think your plans to co-cultivate the two makes a lot of good sense! Best of luck!
@dennis_barron @michael_doall Thanks for the interesting conversation! I've moved this post to the Research and Industry News topic so that others might benefit from the science Mike mentions in this exchange.
@dennis_barron HI dennis, May i ask if you have started operations already? Where in Philippines are you planning for this? Kind regards, Daan