10.5061/DRYAD.SQV9S4N3R
Spindel, Nathan
0000-0002-4853-7427
Florida State University
Lee, Lynn
Parks Canada
Okamoto, Daniel
Florida State University
Metabolic depression in sea urchin barrens associated with food deprivation
Dryad
dataset
2021
2022-04-07T00:00:00Z
2022-04-07T00:00:00Z
en
https://doi.org/10.5281/zenodo.4657754
58599 bytes
2
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
The proliferation of sea urchins can decimate macroalgal forests in
coastal ecosystems, leading to persistent barren seascapes. While kelp
forests are among the most productive ecosystems on the planet,
productivity in these urchin barrens is dramatically reduced. Moreover,
urchins inhabiting these food-depauperate barrens face starvation and many
survive in these barrens for years or decades. Urchins in barrens can
persist by eating food subsidies from drift algae, pelagic salps,
tubeworms, as well as encrusting and filamentous algae, microbial mats,
and slow-growing species resistant to herbivory. Despite both food from
endogenous production and exogenous subsidies, many urchins in barrens
likely experience prolonged food deprivation. This resource limitation may
create a trade-off between reproduction and survival; for example,
fecundity of purple sea urchins (Strongylocentrotus purpuratus) is 99.9%
lower in barrens. Despite food constraints, red sea urchins (Mesocentrotus
franciscanus), the dominant urchin species at our study sites, can live in
excess of 100 years and barrens in Haida Gwaii, British Columbia (BC),
Canada, have persisted for at least 143 years. While these phenomena are
widespread and well documented, the bioenergetic adaptations that allow
urchins to persist in these food-depauperate barrens remain poorly
understood. To quantify habitat-specific differences in metabolic rates
and energy reserves (as measured by gonadal mass), we conducted
respirometry on and measured gonadal mass in M. franciscanus at three
locations in BC inside and outside of adjacent kelp forest and barrens
habitat. Here we demonstrate that M. franciscanus in barrens versus kelp
forests have substantially lower energy reserves and, importantly, also
exhibit dramatic reductions in size-specific resting metabolic rates
(RMR), even after standardizing by metabolically active body mass. On
average, gonadal mass was 44.6% lower and RMR scaled to metabolically
active body mass was 40% lower in barrens urchins than in kelp forest
urchins. Such a shift in metabolic rate may provide a mechanism that
facilitates barren state stability over long time scales as M.
franciscanus can lower energetic demands while they wait for small pulses
of food, scrape by on low-productivity resources, and suppress recruitment
of macroalgae for months, years, or decades.
This respirometry dataset was collected using custom-built sealed chambers
fitted with flow-through optical oxygen sensors and a temperature sensor
(Presens Precision Sensing GmbH). We conducted quality control on oxygen
time series data using the R package respR (Harianto et al. 2019).