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Possible southern reef closure

Discussion in 'Cozumel' started by gopbroek, Sep 21, 2019.

  1. Charred

    Charred Barracuda

    # of Dives: 100 - 199
    Location: Lehigh Valley
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    My wife and 2 friends were in Cozumel last week. We were there in April this year as well as April last year, etc...

    Additionally, for years I very successfully maintained a reef tank that grew stony corals from traded fragments. I consider myself very familiar with coral health and growth.

    All of us agreed the drop in reef health from April to November was staggering. The brain corals are gone. They are just skeleton now with most covered in coralline algae (it looks blue but could be a very thin layer of the typical purple). Many of the hard stony corals look heat stressed to me. The water was 84F. I cant imagine what it was in the summer. 86F? 87F would probably cause a major bleaching event.

    Much of the fire coral is completely bleached. It took me 2 days to find a non-bleached one to point out what a live one looks like.

    On top of the heat stress, the sargasum was in deep piles in the dead zones on the reefs. Think of how leaves collect out of windy areas. The sargasum must be sinking and then its collecting in dead current zones. I found one pile at least 2 feet thick. It is just sitting there decaying release nutrients back into the water. Speaking of nutrients, there is just way too much nuisance algae on the reefs. The decaying sargasum is just going to feed this. These reefs are definitely under full assault from temperature and nutrients.

    Lastly, boats were cheating the the closed reefs. The one time we dove Punta Dalila dropping in right at the pier there were multiple boats 100s of yards further south of us. I'm not suggesting they are hurting the reefs but they are cheating.

    Hopefully the water in the Caribbean cools soon and the corals get some relief. But that sinking sargasum is a new issue an I am unsure what to think about that.
     
  2. tridacna

    tridacna ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: New Jersey
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    As you know, pink calcareous algae used to be a good sign in a reef tank. Oh the irony...!

    Thanks for the report.
     
  3. Charred

    Charred Barracuda

    # of Dives: 100 - 199
    Location: Lehigh Valley
    284
    220
    43
    Ha! Ironically I thought exactly that...."at least it is coralline algae growing and not nuisance algae." It does signal a certain amount of reef health.
     
  4. robint

    robint Orca

    # of Dives: 500 - 999
    Location: Albuquerque, NM
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    Charred - Wow, that sounds horrible. 84 degrees in Nov is bad. Global warming of oceans/weather related.... and not diver related, not cruise ship related.
    The sargassum laying on the reefs is of great concern, to me. I just don't see any "cure" for this at all. It sounds like it will only get worse.
    What are your thoughts about fish life now? I read some reports saying the fish are vanishing also. Not sure if its true, just wondering your thoughts.
     
  5. Dave Dillehay

    Dave Dillehay Dive Shop

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    LOTS of elk horn coral on the east side near Hanan and it is just fine now.

    Dave Dillehay
    Founder and Former partner in Aldora Divers

    PS 84 F is not unusual in early November. It will be 78 F soon..if not I may buy into this theory.
     
    Snoweman likes this.
  6. BRT

    BRT Giant Squid

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    Thanks Dave, I wondered what was normal.
     
  7. Dave Dillehay

    Dave Dillehay Dive Shop

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    Actually 86 F in Summer is absolutely normal at least since 1992. Now not all temp gages are calibrated and that might explain some variations but be sure to expect 78-79 F IN January. If it stays in the 80s then we really do have a problem.

    Dave
     
    cvchief and chillyinCanada like this.
  8. DandyDon

    DandyDon Old men ought to be explorers ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: One kilometer high on the Texas High Plains
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    Here is one record for last January. I have to wonder if their thermometer needs help.

    upload_2019-11-21_15-52-36.png
     
  9. tridacna

    tridacna ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: New Jersey
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  10. DandyDon

    DandyDon Old men ought to be explorers ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: One kilometer high on the Texas High Plains
    48,656
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    113
    tridacna likes this.

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