[Coral-List] Screed from Mike

[Risk, Michael]

   I had a birthday a few days ago, which made me do some thinking.

    Here is what we know.

   -reefs are in desperate shape, worldwide.

   -the decline, in most instances, began mid-19th century, long before
   heat stress had been invoked as a major factor.

   -land-based stresses (LBSP) are a major threat.

   -global warming, left unchecked, will slay every coral reef on the
   planet.

   -We knew about the declining reefs 30 years ago, we knew about CO2 and
   climate for far longer-many thanks to Shell and Exxon, for their
   climate models >50 years ago, showing the impacts. Pity they didn't
   publicize their results.

   Every week it seems there is some new idea that will "save the reefs:"
   killing COTs with robots, saving holothurians, 3D-printing of fake
   corals, breeding super corals that can live in hot polluted
   oceans...though alarmingly, discussions around the root cause of reef
   decline at the very sites of active restoration where it is clear that
   water quality is insufficient to sustain coral reef ecosystems, remain
   missing, with no effort to correct it.

   So it is with a jaundiced eye that I view the present situation. Some
   recent work has convinced me that we can no longer ignore the fact that
   degradation of the ocean's water quality is a mortal enemy of
   restoration, and if it continues to be ignored the battle to restore
   coral reefs is already lost.

   As an indication that this is more than my opinion, here are several
   recent publications, as well as some old facts that support this point
   of view.

   There is ample evidence, from both the Indo-Pacific and the Caribbean,
   that reducing nutrient load on reefs improves their health (Kaneohe
   Bay, Worthing Barbados, etc etc). Then there's that wonderful paper by
   Tomascik et al, 1996: "Rapid coral colonization of a recent lava flow
   following a volcanic eruption, Banda Islands, Indonesia." Coral reefs
   15: 169-175, which I call "Zero to 60 in 5 (years)."  An andesitic lava
   flow entered a bay, promptly dubbed "Air Panas" (Hot Water) by the
   locals. Five years later, that flow supported a coral community with
   >60% coral cover (the level most of us assume reefs attained in those
   prelapsarian times before humans started messing things up), and >100
   coral species. The key, of course, is that this location is free from
   industry and major human habitation. The water is clean. Five years is
   all that is needed to build a healthy reef-if.

   May et al 2022 [1]https://doi.org/10.1371/journal.pone.0278695 worked
   on porewater toxicity in Biscayne Bay, using the sea urchin embryo
   model. (Stick the little critters in the water, watch them die.) At
   over 80% of their sites, the porewater was so toxic that any reef
   growth would be impossible. All sorts of human nasties in the water:
   sewage, pharmaceuticals, ag chemicals. Biscayne Bay isn't the world,
   but it can serve as a model for any reef sitting on porous substrates,
   next to human influence. i.e., most of them. That paper terrified
   me-and it should terrify all of us.

   Yang et al 2024 also scared me.
   [2]https://doi.org/10.1038/s41467-024-46059-4They looked at the impacts
   of herbicides on primary productivity, worldwide, and found a
   significant inhibition at all sites. What's more, there were changes in
   the plankton community. The concept of a reef being outside human
   influence is hard to sustain.

    Li et al 2023 ([3]https://doi.org/10.1016/j.chemosphere.2023.139729)
   investigated the synergistic effects of nitrogen enrichment and
   pesticides (prometryn) on coral metabolism, and found significant
   impairment. "Prometryn exposure increases the oxidative stress induced
   by nitrate enrichment." (from the Abstract).

    Zhou et al, 2024 ([4]https://doi.org/10.1021/acs.est.3c10417) showed
   that...well, what they found is in the title. "Environmental
   Concentrations of Herbicide Prometryn Render Stress-Tolerant Corals
   Susceptible to Ocean Warming." The herbicide overwhelms the coral's
   photosystem repair mechanism. What's worse is that the herbicide may
   actively inhibit the coral's ability to recover from stress.

   In light of these papers, among many others, can the current strategies
   for coral reef restoration succeed without factoring water quality into
   the restoration formula?

   Yours, this lovely and too-early Spring-Mike

References

   1. https://doi.org/10.1371/journal.pone.0278695
   2. https://doi.org/10.1038/s41467-024-46059-4
   3. https://doi.org/10.1016/j.chemosphere.2023.139729
   4. https://doi.org/10.1021/acs.est.3c10417