Is Cozumel still Fishy?

[Jackie]

I first got certified in Cozumel over 20 years ago. While my recollections may not be too accurate, I seem to recall that Wilma did a bit of damage, in particular. Still I have a lot of great times 2010-2020. I was just in Roatan at Cocoview and was stunned at not just the poor conditions of the reefs but also at the lack of fish. On our night dive I saw a turtle, a flounder and an octopus. There is some pretty good macro, even I found a sea horse.
But it felt a little disappointing all round.
I am hearing the same about Caymans and Bonaire,
im going in December and hope it’s as good as I remember, I know that this persistent heat and high sea temperatures are not helping. Is the meso-American reef in decline?

 

[ggunn]

I have seen bait balls twice. Once was huge one on the wreck probably in 2010 or 11. The were the real small sardine size you could swim through an it was mesmerizing. Then a small a small ball snorkeling north about 100 yards out in front just south of Las Brisas. It was not a big bait ball but it was cool, especially for in just 15 feet of water.

Years ago I saw a bait ball while I was snorkeling at what is now Blue Angel in about 15 feet of water. The individual fish were silver and about 2-3 inches long, and there was a bazillion of them. The ball was 8-10 feet in diameter and so dense that I could only see a little way into it.

 

[BoundForElsewhere]

Bait balls are the underwater equivalent of cruise ships.

 

[Snoweman]

I dove in 2019, and thought that I wouldn't be back. Then COVID hit and about the only country we could visit was Mexico. My dive buddy and daughter went in September of 2020 and the reefs were so much better. Dive ops were claiming it was the lack of cruise ships. Me? I thought it was the closure of many hotels south of town. My rash guards would stink the next day if I didn't thoroughly soap them down after a dive in Coz. I didn't have the same problem in FL or Bonaire. I really think the sewerage seeping through the corals from the southern resorts is a bigger problem than people know.

 

[Yellowdog]

For what its worth I dove Cozumel in early August this year and saw several large Permit on the reef and going through a swim through. I have never seen them there while diving before and the dive master mentioned how unusual it was to see one when we surfaced.

 

[BRT]

If you want to swim through lots of fish you need to go to Puerto Morelos on the other side of the channel.

 

[Pipehorse]

@Jackie I cannot speak to the conditions of the reefs in Cozumel because I have not been there to observe them. However I can speak to the question, "Is Cozumel Still Fishy?" even though I have not been there to do fish surveys myself. REEF (Reef Environmental Education Foundation) keeps a database of fish observations world wide. Volunteer scuba divers do fish surveys while they are diving. There are approximately 290,000 surveys world wide, and 190,000 surveys in the Tropical Western Atlantic. If you look at the table below there are 13159 surveys for Cozumel as of today, going back to 1993. I found this information by doing a Geographic Area Report from the REEF website, specifically for Cozumel. The following link if an instructional video how to do a Geographic Area Report How To Do A Geographic Area Report Using Reef Data. This information allows us not to be reliant on anecdotal observations.


So the table below is data separated by year for Cozumel going back to 2013. Total of surveys per year, total species record for that year from all those surveys, and the average number of species recorded on a survey by either an expert or novice. Experts have done at least 45 surveys in a given region and passed a test with a score of 90% for identifying fish of that region. The "AVG" row is for 2022-2013, 2023 is not not included because it is not complete. Total surveys for 2023 seems a little low right now, however REEF does do a field trip for Cozumel every December. Figure 15 divers doing at least 10 surveys each so this would be a large increase for 2023 in the number of surveys recorded.

Conclusion: The number of species present in Cozumel has been remarkably stable over the last ten years.
Average Species observed per year - 258, Min -240, Max 275. + or - 6.7% in any given year.
Expert Surveyors Avg 65 species per survey, with a range of less than + or - 7.6% in any given year.
Novice Surveyors Avg 45 species per survey with at range of range of + or - 17.7%

I apologize if the columns are not in perfect order, this app only allows a max of ten rows when you make a table.

Year	Total Surveys	Total Species	Expert Avg	Novice Avg
1993-2023	13159	466	65	45
2023	139	207	70	53
2022	446	252	69	45
2021	576	272	64	40
2020	326	245	65	46
2019	759	275	64	44
2018	685	268	66	47
2017	640	263	63	46
2016	632	255	66	50

2015	641	240	68	45
2014	581	244	62	41
2013	466	261	63	38

AVG

575

258

65

45

 

[Yellowdog]

@Jackie I cannot speak to the conditions of the reefs in Cozumel because I have not been there to observe them. However I can speak to the question, "Is Cozumel Still Fishy?" even though I have not been there to do fish surveys myself. REEF (Reef Environmental Education Foundation) keeps a database of fish observations world wide. Volunteer scuba divers do fish surveys while they are diving. There are approximately 290,000 surveys world wide, and 190,000 surveys in the Tropical Western Atlantic. If you look at the table below there are 13159 surveys for Cozumel as of today, going back to 1993. I found this information by doing a Geographic Area Report from the REEF website, specifically for Cozumel. The following link if an instructional video how to do a Geographic Area Report How To Do A Geographic Area Report Using Reef Data. This information allows us not to be reliant on anecdotal observations.


So the table below is data separated by year for Cozumel going back to 2013. Total of surveys per year, total species record for that year from all those surveys, and the average number of species recorded on a survey by either an expert or novice. Experts have done at least 45 surveys in a given region and passed a test with a score of 90% for identifying fish of that region. The "AVG" row is for 2022-2013, 2023 is not not included because it is not complete. Total surveys for 2023 seems a little low right now, however REEF does do a field trip for Cozumel every December. Figure 15 divers doing at least 10 surveys each so this would be a large increase for 2023 in the number of surveys recorded.

Conclusion: The number of species present in Cozumel has been remarkably stable over the last ten years.
Average Species observed per year - 258, Min -240, Max 275. + or - 6.7% in any given year.
Expert Surveyors Avg 65 species per survey, with a range of less than + or - 7.6% in any given year.
Novice Surveyors Avg 45 species per survey with at range of range of + or - 17.7%

I apologize if the columns are not in perfect order, this app only allows a max of ten rows when you make a table.

Year	Total Surveys	Total Species	Expert Avg	Novice Avg
1993-2023	13159	466	65	45
2023	139	207	70	53
2022	446	252	69	45
2021	576	272	64	40
2020	326	245	65	46
2019	759	275	64	44
2018	685	268	66	47
2017	640	263	63	46
2016	632	255	66	50

2015	641	240	68	45
2014	581	244	62	41
2013	466	261	63	38

AVG

575

258

65

45

Really interesting. Although not in line with my personal impressions from 15 years of diving there.

 

[ReefHound]

I wonder if there might be a "nostalgia" effect or something where your observations today never match up to your recollections of yesteryear even if there has been little change? Or veteran divers have grown used to what once wowed them?

 

[Joneill]

Really interesting. Although not in line with my personal impressions from 15 years of diving there.

And # of species observed doesn’t necessarily speak to the quantity of those fish seen does it?

 

[Jackie]

Thank you all so much for this information! Just fascinating!

And # of species observed doesn’t necessarily speak to the quantity of those fish seen does it?

good question!