10.5061/DRYAD.2D0G778
Girard, Fanny
Pennsylvania State University
Shea, Katriona
Pennsylvania State University
Fisher, Charles R.
Pennsylvania State University
Data from: Projecting the recovery of a long-lived deep-sea octocoral
species after the Deepwater Horizon oil spill using structured population
models
Dryad
dataset
2019
anthropogenic impact
Cold-water corals
Matrix population models
imagery
Paramuricea biscaya
2019-02-12T00:00:00Z
2019-02-12T00:00:00Z
en
https://doi.org/10.1111/1365-2664.13141
104319 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Deep-water coral communities are hotspots of diversity and biomass in
the deep sea. Most deep-sea coral species are long-lived and slow-growing,
and are thus expected to recover slowly after disturbance. A better
understanding of the recovery potential of these organisms is necessary to
make appropriate management decisions. 2. We used data from high
resolution monitoring of individual coral colonies that were impacted by
the Deepwater Horizon oil spill (April 2010) to parameterise and validate
an annual, impact-dependent, state-structured matrix model to estimate the
time to recovery for each coral colony. We projected the dynamics of three
branch states: visibly healthy, unhealthy and hydroid-colonized. Although
we implicitly included branch loss in the model, we focused on the
short-term return of extant, damaged, branches to a visibly healthy state
and did not consider the far longer-term re-growth of lost branches. 3.
Our model estimates that, depending on the initial level of impact, corals
impacted by the spill will take up to three decades to recover to a state
where all remaining branches appear healthy, though the majority of corals
are projected to reach that state within a decade. By that time, some of
these colonies will have lost a significant number of branches, leading to
approximately 10% reduction in total biomass at all impacted sites. 4.
Overall, our model overestimates recovery, but branch loss estimates were
reliable. Thus, the available growth rate data suggest that hundreds of
years may be necessary for impacted communities to grow back to their
initial biomass. 5. Policy implications. Our study quantifies the very
slow recovery rate of deep-sea corals and demonstrates the imperative of
prioritizing a precautionary approach for these deep-sea ecosystems over
restoration after the fact. As anthropogenic pressure on the deep sea is
likely to increase, we suggest the establishment of coral-monitoring sites
implemented as part of Marine Protected Areas to limit and detect impact
to deep-sea corals. Furthermore, estimates from our model may be used to
plan short- and longer-term monitoring programmes after impact and to
provide a timeline for policy.09-Feb-2018
R script for the modelModel_script.RTransition values for healthy branches
(2011-2015)All values were estimated from digitized images of individual
coral colonies. Abbreviations: Coral (individual colony identifier), Total
(total number of branches), Total nv (total number of healthy branches),
nv_to_nv, nv_to_nh, nv_to_hy (number of healthy branches that transitioned
to healthy, unhealthy or hydroid-colonized, respectively, Impact (total
visible impact proportion), Size (total coral size (m)), Site, Year
(imaging year).nv_counts_size_novn_MC294_11-15.csvTransition values for
unhealthy branches (2011-2015)All values were estimated from digitized
images of individual coral colonies. Abbreviations: Coral (individual
colony identifier), Total (total number of branches), Total nh (total
number of unhealthy branches), nh_to_nv, nh_to_nh, nh_to_hy (number of
unhealthy branches that transitioned to healthy, unhealthy or
hydroid-colonized, respectively, Impact (total visible impact proportion),
Size (total coral size (m)), Site, Year (imaging
year).nh_counts_size_novn_MC294_11-15.csvTransition values for branches
colonized by hydroids (2011-2015)All values were estimated from digitized
images of individual coral colonies. Abbreviations: Coral (individual
colony identifier), Total (total number of branches), Total hy (total
number of branches colonized by hydroids), hy_to_nv, hy_to_nh, hy_to_hy
(number of hydroid-colonized branches that transitioned to healthy,
unhealthy or hydroid-colonized, respectively, Impact (total visible impact
proportion), Size (total coral size (m)), Site, Year (imaging
year).hy_counts_size_novn_MC294_11-15.csvNumber of branches in each state
in 2011Number of branches in each state in 2011 (initial conditions) for
every coral colony at MC 294, MC 297 and MC
344.initial_impact_counts.csvCoral size in 2011Size (m) of every coral
colony at MC 294, MC 297 and MC 344.initial_size.csvAverage coral size
used for model simulationsAverage coral size (m) calculated based on coral
colonies from MC 294, MC 297 and MC
344.initial_size_simulations_100_170br.csvProportions of unhealthy and
hydroid-colonized branchesProportions of unhealthy and hydroid-colonized
branches for every coral colony at MC 294, MC 297 and MC
344.impact_values.csv
Gulf of Mexico