10.5061/DRYAD.7VG42
Salvatteci, Renato
Field, David B.
Pacific University
Baumgartner, Timothy
Ferreira, Vicente
Gutierrez, Dimitri
Data from: Evaluating fish scale preservation in sediment records from the
oxygen minimum zone off Peru
Dryad
dataset
2011
past fish population variability
Sardinops sagax sagax
Little Ice Age to the present
Humboldt Current
fish scales
marine laminated sediments
Engraulis ringens
2011-07-12T17:58:13Z
2011-07-12T17:58:13Z
en
https://doi.org/10.1666/10045.1
154738 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Fish scales accumulating in marine laminated sediments can provide a
record of population variability of small pelagic fishes. Although some
studies have noted signs of scale degradation that could affect estimates
of population variability, there are presently no well-developed means to
evaluate degradation. We developed several indices as indicators of fish
scale preservation in two box-cores that we collected off Pisco (14ºS),
one at 301 m near the center of the oxygen minimum zone (OMZ), and the
other at 201 m near the upper limit of the OMZ. These indices include (1)
an index of fish scale integrity (estimate of scale wholeness relative to
fragmentation), (2) the fungi-free area of fish scales and vertebrae, (3)
the ratio of fish scales to vertebrae (as well as fish scales to vertebrae
and bones), and (4) the ratio of whole scales to fragments. We address
whether lower numbers of anchovy scales occurring in association with
reduced total organic carbon fluxes and higher bottom-water oxygen
concentrations are due entirely to lower abundances of anchovy or whether
differential preservation of the fish scales in the sediments plays an
important role in reduced scale abundances. Comparison of temporal
sequences between the two cores provides the means to assess whether there
are differences in the preservation of fish scales. The combined indices
indicate that the lower numbers of fish scales in the earliest period have
been affected by degradation, and to a greater degree in the box-core from
201 meters, which can be subject to higher oxygen concentrations. On the
other hand, decadal-scale variations in fish scale abundance within the
period of better preservation are unlikely to be caused by degradation. We
discuss the utility and drawbacks of different indices of preservation for
reconstructing past changes in fish population sizes with fluxes of fish
debris and also briefly discuss the utility of these indices to other
paleobiological systems.
Ms 10045 data Salvatteci et al
Peru
Pisco