Lionfish Impact III-We've Got Crabs!

Building a case for the positive impacts of the Lionfish colonization of the Atlantic and Caribbean coral reefs, I introduce a group of herbivorous crabs. These crabs are a largely uncredited key player in reducing algal cover on the coral reefs and Lionfish are inadvertently acting as their bodyguards.

For a better view of a Channel Clinging Crab;
http://www.youtube.com/watch?v=zB_h3azr8C0

Information on why the purple rock is good can be found in some of the work of Dr. Alina Szmant who did extensive work on coral larvae settlement.

Information on the toxic nature of some reef algae can be found in the work of Dr. Mark Hay

Category:

Science & Technology

Tags:

• lionfish
• crabs
• marine
• biology
• invasive
• species
• scuba
• diving
• Bahamas
• Grand
• Bahama
• ecology

[duanefey]

Fred, great videos, I, II and III. Just one question, why is Kamokoi so negative and arrogant? Oh well, maybe nobody will listen to him...I wonder why. Great to see you and Melinda again, it was way too long in between trips. Keep up the good work! Duane

[NaguShiiaRen]

@kamokoi.....i'm not experienced in any way of this area.......but what i do want to know is, why is most of your comments about other people's work, and research with only of few of actually your own research. How about you post some videos to educate the rest of us, and explain your research and observation and not some other people's work, facts, or hypotheses. To me, this video shows the sea life that Fred has recorded which also shows the actions with him explaining it.

[domdiver1]

Great video!

[kamokoi]

@Fredgbscuba The fact that science corrects itself does not represent a good argument for ignoring it. You should not confuse your undocumented unquantified observations as research.

[kamokoi]

@Fredgbscuba I do not deny your education, experience or observations. I do deny your arguments in favor of hypotheses supported solely by anecdotal evidence when they go against hypotheses that are backed by quantitative data and experiments conducted by scientists (particularly those that have made it through the rigorous peer-review process).

[kamokoi]

@Fredgbscuba We have found crabs and crab parts that we have identified as belonging to members of the genus Mithrax (clinging crabs) among others. We do not have verified species level identifications, however I do not believe that this makes the data insignificant as you suggest. Do you?

[kamokoi]

@Fredgbscuba Obviously lionfish eat. Obviously other native organisms eat. I am not, "...denying that everything else eats." There is, however, no evidence (quantitative or experimental) that small crustaceans (like the small crabs in your video) contribute significantly to overall grazing rates on coral reefs. It is great that you are thinking outside the box.  However, I don't think that you should be presenting your ideas as if they are facts without the data to back them up.

[kamokoi]

@Fredgbscuba As you say, knowledge marches on. However, the fact that science is in a constant state of refinement doesn't mean that we should throw out hypothesis that have a lot of empirical support because we don't like them. That's why rigorous experimentation and quantitative observations are conducted. You have done neither, and yet you expect folks to throw out supported hypotheses based on your best guesses as to why you are seeing what you are seeing.

[kamokoi]

@Fredgbscuba Parrotfishes do eat a certain amount of coral (usually this is dead coral skeleton covered in turf algae rather than live coral), and they do "crap sand" and contribute to beach sand accumulation. They also eat a large proportion of fleshy macroalgae. I'm not sure how this is relevant to the discussion.

[kamokoi]

@Fredgbscuba I have done stomach content analyses on lionfish. I have also conducted over 1000 scientific research dives over the last five years, specifically for the purpose of investigating invasive lionfish and their effects on native communities. I do not say this because I want to get into a bragging match with you. However, I do want you to understand that I have spent a considerable amount of time and effort towards understanding this invasion.