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Monitoring the Ocean with Cephalopods

DWhatley

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Fish getting smaller as the oceans get warmer

Short article in Practical Fishkeeping that summarizes findings that fish are getting small as oxygen decreases.

I found several references to the study findings, this one in Science Daily but not an accessable copy of the study (published in the Sept 30, 2012 Nature Climate Change journal).

What makes this a somewhat ceph related item is the findings Dr Gilly published about the Humboldt squid becoming smaller, breeding sooner and living shorter lives with the reduction in food supply. The summary article did not mention the other two observations or take into account food supply so the only exposed commonality is size reduction but It is significant to note that we think we are seeing animal size changes in a single life time.
 

DWhatley

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Esterification of vertebrate like steroids in molluscs: A target of endocrine disruptors?

Arnaud Giusti​, Célia Joaquim-Justo Aug 2013
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Abstract

Alterations of the reproductive organs of gastropod molluscs exposed to pollutants have been reported in natural populations for more than 40 years. In some cases these impacts have been linked to exposure to endocrine disrupting chemicals (EDCs), which are known to induce adverse impacts on vertebrates, mainly by direct binding to steroid receptors or by altering hormone synthesis. Investigations on the mechanisms of action of endocrine disruptors in molluscs show that EDCs induce modifications of endogenous titres of androgens (e.g., testosterone, androstenedione) and oestrogens (e.g., 17ß-oestradiol). Alterations of the activity of enzymes related to steroid metabolism (i.e., cytochrome P450 aromatase, acyltransferases) are also often observed. In bivalves and gastropods, fatty acid esterification of steroids might constitute the major regulation of androgen and oestrogen homeostasis. The present review indicates that metabolism of steroid hormones to fatty acid esters might be a target of synthetic EDCs. Alterations of this process would impact the concentrations of free, potentially bioactive, form of steroids.
 

DWhatley

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The effect of thermal processing and canning on cadmium and lead levels in California market squid: the role of metallothioneins A. Galitsopoulou, D. Georgantelis, M.G. Kontominas May 2013
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Abstract

The effects of two common seafood preparation practices (roasting and industrial canning) on the heavy metal content (Cd, Pb) of various tissues of California market squid were studied. Emphasis was placed on the role of metallothioneins (MT) in Cd and Pb behaviour during processing. Cadmium and lead analysis was conducted by a Zeeman GTA-AAS atomic absorption spectrometry system and MT analysis was performed by a mercury saturation assay. Results showed that Cd levels in the mantle and whole squid were considerably affected by both processing practices, reaching a 240% increase in mantle and a 40% increase in whole squid. Interestingly, Cd behaviour was associated to MT changes during squid processing. On the other hand, Pb content was not affected neither from processing or associated to MT content in the raw or processed squid. Therefore, processing operations may affect Cd and Pb content differently, due to the specific metal bioaccumulation and chemical features of each heavy metal type.
 
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GPO87

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This is an excellent thread to start, D. Great thinking! I've recently started to consider the effect of ocean changes on cephalopod life, particularly as it pertains to acidification.
 

DWhatley

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Developmental and physiological challenges of octopus (Octopus vulgaris) early life stages under ocean warming

Tiago Repolho,Miguel Baptista,Marta S. Pimentel,Gisela Dionísio,Katja Trübenbach,Vanessa M. Lopes,Ana Rita Lopes,Ricardo Calado,Mário Diniz,Rui Rosa
2013

Abstract The ability to understand and predict the effects of ocean warming (under realistic scenarios) on marine biota is of paramount importance, especially at the most vulnerable early life stages. Here we investigated the impact of predicted environmental warming (+3 °C) on the development, metabolism, heat shock response and antioxidant defense mechanisms of the early stages of the common octopus, Octopus vulgaris. As expected, warming shortened embryonic developmental time by 13 days, from 38 days at 18 °C to 25 days at 21 °C. Concomitantly, survival decreased significantly (~29.9 %). Size at hatching varied inversely with temperature, and the percentage of smaller premature paralarvae increased drastically, from 0 % at 18 °C to 17.8 % at 21 °C. The metabolic costs of the transition from an encapsulated embryo to a free planktonic form increased significantly with warming, and HSP70 concentrations and glutathione S-transferase activity levels were significantly magnified from late embryonic to paralarval stages. Yet, despite the presence of effective antioxidant defense mechanisms, ocean warming led to an augmentation of malondialdehyde levels (an indicative of enhanced ROS action), a process considered to be one of the most frequent cellular injury mechanisms. Thus, the present study provides clues about how the magnitude and rate of ocean warming will challenge the buffering capacities of octopus embryos and hatchlings’ physiology. The prediction and understanding of the biochemical and physiological responses to warmer temperatures (under realistic scenarios) is crucial for the management of highly commercial and ecologically important species, such as O. vulgaris.
 

DWhatley

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Interspecific and geographical variations of trace metal concentrations in cephalopods from Tunisian waters
Moncef Rjeibi, Marc Metian, Tarek Hajji, Thierry Guyot, Rafika Ben Chaouacha-Chékir, Paco Bustamante 2014 (subscription)
Abstract
The concentrations of six metals (Ag, Cd, Cu, Hg, Pb, and Zn) were investigated and compared in three tissues (arms, digestive gland, and mantle) of three cephalopod species from the Tunisian waters: the common octopus (Octopus vulgaris), the common cuttlefish (Sepia officinalis), and the European squid (Loligo vulgaris). Whatever the species or the sites, the digestive gland displayed the highest concentrations of Ag, Cd, Cu, Pb, and Zn, highlighting its major role in their bioaccumulation and detoxification. This is also true for Hg but only for the digestive gland of O. vulgaris. Muscle from the arms and the mantle contained thus relatively low trace metal concentrations except for Hg in L. vulgaris and S. officinalis. Geographic comparison of metal concentrations in Tunisian cephalopods from three locations indicates that higher concentrations of Ag, Pb, and Hg were observed in cephalopods from northern and eastern coasts, whereas the highest Cd levels were detected in the southeastern, reflecting different conditions of exposure. Comparing the trace element concentrations between species, Ag, Cd, Cu, Hg, and Zn concentrations were the highest in the digestive gland of octopuses. This may be related to the differences in ecological features and swimming behavior among different cephalopod species. Effects of length and sex on metal levels were also considered, indicating a limited influence of sex on metal concentration.
 

gjbarord

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I think there are some papers on the effect of changing oceans on cuttlebones that might actually increase growth rates, whether that's good or bad in the end, who knows...

Greg
 

DWhatley

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The future of cephalopod populations, fisheries, culture, and research in Europe Cephalopod biology and fisheries in Europe 2006 (full pdf)

@gjbarord , you make me work too hard! I think this may be the article (or includes a summary of the study) you remember.
Rosa and Seibel (2008) demonstrated that ocean acidification will substantially depress metabolic rates (31 %) and activity levels (45 %) in the jumbo squid (Dosidicus gigas) and that the effect will be exacerbated by high temperature. However, Gutowska et al. (2008) found that juvenile cuttlefish
maintained not only calcification, but also their growth rates and metabolism when exposed to elevated partial pressures of CO2. They suggest that active cephalopods possess a certain level of pre‐adaptation to long‐term increments in CO2 levels.
It was probably worth the effort to find as it give an interesting case for using cephalopods to monitor climate change.

The combination of sensitivity and adaptability of cephalopods to climate variation, seen in individual life‐history parameters and population processes, and mediated through direct physiological effects and the indirect consequences of effects on other species, makes cephalopods potentially useful indicators of climate change. In addition, the presence of recording structures, such as the beak, gladius, and cuttlebone, means that the environmental conditions experienced over an animal’s lifetime, and its responses, are recorded in terms of isotope ratios and increment sizes, etc., affording the prospect of improved understanding of the mechanisms by which the environment affects the individual.
 

DWhatley

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Ocean acidification and temperature rise: effects on calcification during early development of the cuttlefish Sepia officinalis
Narimane Dorey, Frank Melzner, Sophie Martin, Franc¸ois Oberha¨nsli, Jean-Louis Teyssie, Paco Bustamante, Jean-Pierre Gattuso, Thomas Lacoue-Labarthe 2011 (full pdf)

I believe this is the study @gjbarord mentioned

The results of this study demonstrate the particularities of the response to acidi?cation in both in embryos and juveniles cuttle?sh, in comparison with other invertebrates. Calci?cation processes under elevated pCO2 in cephalopods need to be better characterized in order to clarify the mechanisms leading to hypercalcifcation in this group. Although the combined effects of ocean acidi?cation and temperature did not decrease calcium accumulation during
the formation of the calcareous endoskeleton in S. Officinalis embryos and juveniles, the functional properties of the cuttlebone as buoyancy device could be affected. The effect of raised pCO2 should be investigated on the animal entire life cycle considering possible carry-over effects (e.g., Parker et al. 2012; Dupont et al. 2012) and not only from the calcifcation point of view. Linked to buoyancy abilities, further studies on feeding behavior under projected scenarios of future environmental change would be required in order to assess CO2 impacts on population dynamics of the cuttlefish S. Officinalis.
 

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