498
these endpoints, many of which were successfully used in recent years to assess
sublethal health impacts on marine fish as part of the response to the DWH spill. We
compare what is known about differences in sensitivity, among species, and between
age classes within species, examining both organismal and molecular endpoints.
Developmental impacts on cardiac health, swim performance, and sensory systems
have been widely studied. We discuss what is known about effects on fish immune
and endocrine function, the microbiome of the intestine and gill, and intracellular
effects such as altered gene expression, oxidative stress, and DNA damage. In conclusion, we attempt to compare the endpoints, assess the sensitivity and utility, and
link molecular- and individual-level impacts to larger population and communitylevel effects.
Keywords ELS (early life stage) · Cardiotoxicity · CEWAF (chemically enhanced
water accommodated fraction) · WAF (water accommodated fraction) · Toxicity
testing · Microbiome · Immune function · RNA sequencing
29.1 Introduction
The response to the 2010 Deepwater Horizon (DWH) oil spill lead to a number of
peer-reviewed publications examining the effects of the released oil and dispersant
on fish species found in the northern Gulf of Mexico (GoM). Many of these papers,
for very good reasons, focused on assessing toxicity by defining lethality through
identification of dose-response curves that were specific to a given species, age
class, exposure type, oil preparation method, and many other factors. Often those
dose-response curves were used to predict LC or EC50 concentrations – amounts of
oil that produced an effect on 50% of the exposed organisms. The advantage of this
approach is obvious, in that it provides a single point estimate and variance of a
concentration required to produce a given effect. This point estimate can then be
compared across different exposure regimes to compare susceptibilities. Relevant
LC/EC50 data is summarized and discussed in A synthesis of DWH oil, chemical
dispersant and chemically dispersed oil aquatic standard laboratory acute and
chronic toxicity studies (see Mitchelmore et al. 2020). By constraining toxicity to
this point estimate (often of lethality), however, researchers run the risk of missing
effects that evince more subtle effects that do not manifest themselves as overt mortality in the short term. In the present chapter, we focus exclusively on fish and
explore some of these endpoints, many of which were successfully used in recent
years to assess sublethal health impacts on marine fish as part of the response to the
DWH spill. We compare what is known about differences in sensitivity, among species, and between age classes within species, examining both organismal and
molecular endpoints. Developmental impacts on cardiac health, swim performance,
and sensory systems have been widely studied. We discuss what is known about
effects on fish immune and endocrine function, the microbiome of the intestine and
gill, and intracellular effects such as altered gene expression, oxidative stress, and
M. Grosell et al.
these endpoints, many of which were successfully used in recent years to assess
sublethal health impacts on marine fish as part of the response to the DWH spill. We
compare what is known about differences in sensitivity, among species, and between
age classes within species, examining both organismal and molecular endpoints.
Developmental impacts on cardiac health, swim performance, and sensory systems
have been widely studied. We discuss what is known about effects on fish immune
and endocrine function, the microbiome of the intestine and gill, and intracellular
effects such as altered gene expression, oxidative stress, and DNA damage. In conclusion, we attempt to compare the endpoints, assess the sensitivity and utility, and
link molecular- and individual-level impacts to larger population and communitylevel effects.
Keywords ELS (early life stage) · Cardiotoxicity · CEWAF (chemically enhanced
water accommodated fraction) · WAF (water accommodated fraction) · Toxicity
testing · Microbiome · Immune function · RNA sequencing
29.1 Introduction
The response to the 2010 Deepwater Horizon (DWH) oil spill lead to a number of
peer-reviewed publications examining the effects of the released oil and dispersant
on fish species found in the northern Gulf of Mexico (GoM). Many of these papers,
for very good reasons, focused on assessing toxicity by defining lethality through
identification of dose-response curves that were specific to a given species, age
class, exposure type, oil preparation method, and many other factors. Often those
dose-response curves were used to predict LC or EC50 concentrations – amounts of
oil that produced an effect on 50% of the exposed organisms. The advantage of this
approach is obvious, in that it provides a single point estimate and variance of a
concentration required to produce a given effect. This point estimate can then be
compared across different exposure regimes to compare susceptibilities. Relevant
LC/EC50 data is summarized and discussed in A synthesis of DWH oil, chemical
dispersant and chemically dispersed oil aquatic standard laboratory acute and
chronic toxicity studies (see Mitchelmore et al. 2020). By constraining toxicity to
this point estimate (often of lethality), however, researchers run the risk of missing
effects that evince more subtle effects that do not manifest themselves as overt mortality in the short term. In the present chapter, we focus exclusively on fish and
explore some of these endpoints, many of which were successfully used in recent
years to assess sublethal health impacts on marine fish as part of the response to the
DWH spill. We compare what is known about differences in sensitivity, among species, and between age classes within species, examining both organismal and
molecular endpoints. Developmental impacts on cardiac health, swim performance,
and sensory systems have been widely studied. We discuss what is known about
effects on fish immune and endocrine function, the microbiome of the intestine and
gill, and intracellular effects such as altered gene expression, oxidative stress, and
M. Grosell et al.