Ocean Warming Effects on Growth, Reproduction, and Survivorship of Southern California Abalone

Abstract

Traditional fisheries management in southern California has failed, in part because it is based on an assumption of an unvarying environment and is focused on size limits rather than insuring the persistence of aggregations of large fecund individuals. The combined effect of low frequency climatic variability and anthropogenic perturbations can have dramatic consequences for abalone in southern California. Abalone species are tightly linked to kelp forest ecosystems that, besides furnishing habitat, also provide the main food source for abalone. In southern California, kelp canopies are very sensitive to oceanographic climate because the kelp depend upon high nutrients in the water column. Oceanic warming, in turn, results in decreased nutrients in the surface water, and this is correlated with marked reductions in giant kelp biomass. Here we address the additive effects of ocean warming on two species of California abalone (the red abalone, Haliotis rufescens; and the green abalone, H. fulgens) by subjecting them to varied environmental conditions similar to cool, normal, and warm phases of the California current in the southern California Bight. Our experimental design simultaneously tested the synergistic effects of temperature and food quantity and quality on survivorship, growth, and reproduction. For red abalone, warm temperatures increased the onset of withering syndrome, a fatal abalone disease, and halted growth and reproduction. In contrast, green abalone survivorship, growth, and reproduction were relatively robust irrespective of temperature, while their growth and reproduction were most strongly influenced by food quantity. We found clear evidence suggesting that, combined with overfishing, California abalone populations are adversely affected by ecosystem responses to ocean warming: Cool‐water red abalone suffer stronger consequences in warm water than do green abalone. Conservation, restoration, and recovery plans of remnant California abalone populations must consider these relationships when taking any action.

Forecasting the combined effects of disparate disturbances on the persistence of long-lived gorgonians: a case study of Paramuricea clavata

“…The repercussions of global warming on the recovery of endangered species are of strong importance to conservation (Hoyle & James 2005, Vilchis et al 2005. Our findings corroborate that the combined effects of local human impacts (in this case diving activity, but in other areas pollution, fishing, and other localized impacts), together with the global warming effects, can dramatically reduce the viability of long-lived and slow-growing marine species.…”

“…For the most pessimistic scenario of 5 yr frequencies of events, the time of quasi-extinction increased from 37 to 60 yr with increasing adult survival in normal years, equivalent to reduced diver impacts. The effects of diving control are much more pronounced at lower mass mortality frequencies, further indicating their feasibility as an indirect and temporary, but effective, management tool in the face of global change.The repercussions of global warming on the recovery of endangered species are of strong importance to conservation (Hoyle & James 2005, Vilchis et al 2005. Our findings corroborate that the combined effects of local human impacts (in this case diving activity, but in other areas pollution, fishing, and other localized impacts), together with the global warming effects, can dramatically reduce the viability of long-lived and slow-growing marine species.…”

“…Mar Ecol Prog Ser 402: [59][60][61][62][63][64][65][66][67][68] 2010 impacts from multiple stressors on individual fitness and population viability (Hughes & Connell 1999, Vilchis et al 2005. Understanding the risks that these impacts and their interacting effects pose for the viability of disturbed populations may be essential in devising criteria for effective management of these species, especially in the face of global change.…”

Supply-side biogeography: geographic patterns of settlement and early mortality for a barnacle approaching its range limit

“…Larval production was relatively uniform among locations, suggesting that the reduction in seawater and air temperatures towards the southern range limit does not limit the ability of Tesseropora rosea to produce larvae. This is perhaps surprising because studies have shown that such differences in seawater temperatures can influence the reproductive ability of benthic marine invertebrates (Brey 1995, Vilchis et al 2005, and field investigations have detected reduced fecundity at range limits due to changes in seawater temperature (Barber & Blake 1983, Amaro et al 2005). However, Helmuth et al (2006) assessed body temperatures of the intertidal mussel Mytilus californianus across a latitudinal gradient in sea-surface temperatures and found that body temperatures were often hotter or colder than was predicted from sea-surface temperatures.…”

Effects of salinity on the growth and mucous cells of the abalone Haliotis diversicolor Reeve, 1846

“…Generally, the effect of temperature on growth of various abalone species would depend on what temperature range they are exposed to in their natural environment. For instance, in California the abalone Haliotis rufescens Swainson that inhabits deep cool water has been reported to decrease growth at increasing temperature, whereas the abalone Haliotis fulgens Philippi that inhabits warm water has increased 12.8 ± 0.6 b 9.1 ± 0.6 b 64.6 ± 7.3 ab Different letters superscript indicate significant differences (ANOVA, df = 4, P = \0.001, Tukey test), common letters indicate no significant differences (P = 0.06) growth at higher temperature (Vilchis et al 2005). On the other hand, in Chile the abalones Haliotis discus hannai Ino and H. rufescens cultured in tank systems have low growth during austral winter and high growth during the austral summer Mardones et al (2013).…”