Shifting baselines of coral‐reef species composition from the Late Pleistocene to the present in the Florida Keys

Abstract The ongoing global‐scale reassembly of modern coral reefs is unprecedented compared with the observed stability of most late Quaternary reef assemblages. One notable exception is the marine isotope stage (MIS) 5e (ca 130–116 thousand years ago [ka]) reefs in the Florida Keys, where the ubiq...

Full description

Saved in:
Bibliographic Details
Main Authors: Lauren T. Toth, Anastasios Stathakopoulos, Scarlette Hsia, David Weinstein
Format: Article
Language:English
Published: Wiley 2025-06-01
Series:The Depositional Record
Subjects:
Online Access:https://doi.org/10.1002/dep2.70009
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850221073880055808
author Lauren T. Toth
Anastasios Stathakopoulos
Scarlette Hsia
David Weinstein
author_facet Lauren T. Toth
Anastasios Stathakopoulos
Scarlette Hsia
David Weinstein
author_sort Lauren T. Toth
collection DOAJ
description Abstract The ongoing global‐scale reassembly of modern coral reefs is unprecedented compared with the observed stability of most late Quaternary reef assemblages. One notable exception is the marine isotope stage (MIS) 5e (ca 130–116 thousand years ago [ka]) reefs in the Florida Keys, where the ubiquitous shallow‐water coral, Acropora palmata, was near absent. Little is known, however, about reefs that grew during MIS5d–a (ca 116–74 ka), between MIS5e and the Holocene. It is therefore unclear whether Florida's unique MIS5e coral assemblages represent a geologically brief anomaly or a more persistent departure from the western Atlantic coral‐reef archetype. We addressed that question by reconstructing the composition of MIS5d–a reefs within 29 coral‐reef cores collected throughout the Florida Keys. We then compared the relative composition of corals during MIS5d–a to existing datasets from MIS5e, Holocene and modern (1996 and 2022) reefs to evaluate how far today's reef assemblages have diverged from geological baselines. We show that although the proportion of reef frameworks built by corals was remarkably consistent (ca 38%), species composition changed significantly through time. Acropora palmata was rare throughout MIS5, which we hypothesise was due to greater cold‐temperature stress in Florida's subtropical reefs compared with the more climatically stable tropics. In contrast, the massive reef‐building coral, Orbicella spp., was regionally dominant throughout the late Quaternary, but has become increasingly rare on modern reefs. By 2022, reefs in the Florida Keys were characterised by a truly novel coral assemblage dominated by Porites astreoides and Siderastrea siderea. In many ways, Florida's reefs defy the concept of a natural baseline; instead, their most persistent characteristic since the Late Pleistocene is their uniqueness. Yet, as reefs are increasingly subjected to unprecedented levels of environmental change, the exceptions to what was normal in the past could, paradoxically, provide the best geological analogues for the future.
format Article
id doaj-art-0f6e6375f0bf49c69e7b07bea7b6003f
institution OA Journals
issn 2055-4877
language English
publishDate 2025-06-01
publisher Wiley
record_format Article
series The Depositional Record
spelling doaj-art-0f6e6375f0bf49c69e7b07bea7b6003f2025-08-20T02:06:49ZengWileyThe Depositional Record2055-48772025-06-0111389391610.1002/dep2.70009Shifting baselines of coral‐reef species composition from the Late Pleistocene to the present in the Florida KeysLauren T. Toth0Anastasios Stathakopoulos1Scarlette Hsia2David Weinstein3U.S. Geological Survey St. Petersburg Coastal and Marine Science Center St. Petersburg Florida USAU.S. Geological Survey St. Petersburg Coastal and Marine Science Center St. Petersburg Florida USAU.S. Geological Survey Florence Bascom Geoscience Center Reston Virginia USAThe Meridian Group Alexandria Virginia USAAbstract The ongoing global‐scale reassembly of modern coral reefs is unprecedented compared with the observed stability of most late Quaternary reef assemblages. One notable exception is the marine isotope stage (MIS) 5e (ca 130–116 thousand years ago [ka]) reefs in the Florida Keys, where the ubiquitous shallow‐water coral, Acropora palmata, was near absent. Little is known, however, about reefs that grew during MIS5d–a (ca 116–74 ka), between MIS5e and the Holocene. It is therefore unclear whether Florida's unique MIS5e coral assemblages represent a geologically brief anomaly or a more persistent departure from the western Atlantic coral‐reef archetype. We addressed that question by reconstructing the composition of MIS5d–a reefs within 29 coral‐reef cores collected throughout the Florida Keys. We then compared the relative composition of corals during MIS5d–a to existing datasets from MIS5e, Holocene and modern (1996 and 2022) reefs to evaluate how far today's reef assemblages have diverged from geological baselines. We show that although the proportion of reef frameworks built by corals was remarkably consistent (ca 38%), species composition changed significantly through time. Acropora palmata was rare throughout MIS5, which we hypothesise was due to greater cold‐temperature stress in Florida's subtropical reefs compared with the more climatically stable tropics. In contrast, the massive reef‐building coral, Orbicella spp., was regionally dominant throughout the late Quaternary, but has become increasingly rare on modern reefs. By 2022, reefs in the Florida Keys were characterised by a truly novel coral assemblage dominated by Porites astreoides and Siderastrea siderea. In many ways, Florida's reefs defy the concept of a natural baseline; instead, their most persistent characteristic since the Late Pleistocene is their uniqueness. Yet, as reefs are increasingly subjected to unprecedented levels of environmental change, the exceptions to what was normal in the past could, paradoxically, provide the best geological analogues for the future.https://doi.org/10.1002/dep2.70009Acropora palmatacoral reefsFloridageological analogueLate PleistoceneMIS5
spellingShingle Lauren T. Toth
Anastasios Stathakopoulos
Scarlette Hsia
David Weinstein
Shifting baselines of coral‐reef species composition from the Late Pleistocene to the present in the Florida Keys
The Depositional Record
Acropora palmata
coral reefs
Florida
geological analogue
Late Pleistocene
MIS5
title Shifting baselines of coral‐reef species composition from the Late Pleistocene to the present in the Florida Keys
title_full Shifting baselines of coral‐reef species composition from the Late Pleistocene to the present in the Florida Keys
title_fullStr Shifting baselines of coral‐reef species composition from the Late Pleistocene to the present in the Florida Keys
title_full_unstemmed Shifting baselines of coral‐reef species composition from the Late Pleistocene to the present in the Florida Keys
title_short Shifting baselines of coral‐reef species composition from the Late Pleistocene to the present in the Florida Keys
title_sort shifting baselines of coral reef species composition from the late pleistocene to the present in the florida keys
topic Acropora palmata
coral reefs
Florida
geological analogue
Late Pleistocene
MIS5
url https://doi.org/10.1002/dep2.70009
work_keys_str_mv AT laurenttoth shiftingbaselinesofcoralreefspeciescompositionfromthelatepleistocenetothepresentinthefloridakeys
AT anastasiosstathakopoulos shiftingbaselinesofcoralreefspeciescompositionfromthelatepleistocenetothepresentinthefloridakeys
AT scarlettehsia shiftingbaselinesofcoralreefspeciescompositionfromthelatepleistocenetothepresentinthefloridakeys
AT davidweinstein shiftingbaselinesofcoralreefspeciescompositionfromthelatepleistocenetothepresentinthefloridakeys