Cadmium Removal from Giant Squid (Dosidicus gigas) Hydrolysate in Fixed-Bed Columns Packed with Iminodiacetic Resin: Tools for Scaling up the Process

Giant squid hydrolysate (GSH) elaborated from different batches from a fishing company was evaluated for cadmium removal. Fixed-bed column packed with iminodiacetic resin as adsorbent was used. GSH solution at different cadmium concentrations were fed in the fixed-bed column and breakthrough curves were evaluated. A high degree of metal removal from the solution was achieved and the saturation point (Ce/C0 ≤ 0.8) was achieved more quickly at higher concentrations of cadmium. The maximum capacity of adsorption (q0) was obtained using the Thomas model, where 1137.4, 860.4, 557.4, and 203.1 mg g−1 were achieved using GSH with concentrations of 48.37, 20.97, 12.13, and 3.26 mg L−1, respectively. Five cycles of desorption of the resin with HCl (1 M) backflow and regeneration with NaOH (0.5 M) were also evaluated, where no significant differences (p-value > 0.05) were observed between each cycle, with an average of 935.9 mg g−1 of qmax. The in-series columns evaluated reached a total efficiency of 90% on average after the third column in GSH with a cadmium concentration of 20.97 mg L−1. This kind of configuration should be considered the best alternative for cadmium removal from GSH. Additionally, the chemical composition of GSH, which was considered a quality parameter, was not affected by cadmium adsorption.

Vulnerability to Climate Change of “Giant Squid” (Thysanoteuthis rhombus) Fishery in Marinduque, Philippines

The Philippine fisheries sector has been affected by the impacts of climate change. Vulnerability to climate change pertains to a natural system's ability to cope with the negative impacts of climate change, variability, and extremes. Vulnerability Assessment (VA) provides a framework for climate change impacts evaluation over a broad range of systems. Tools such as Fisheries Vulnerability Assessment Tool (Fish Vool) have been developed to do VA. The "giant squid" diamondback (Thysanoteuthis rhombus) fishery in the province of Marinduque is an essential source of food and livelihood in the area. However, its vulnerability to climate change impacts has not been assessed. In this study, the "giant squid" fishery in Gasan, Marinduque, was assessed using Fish Vool. Results revealed that overall climate change vulnerability of the fishery is high, where both sensitivity and adaptive capacity are medium while exposure is high. Overall, the study provided a better understanding of the "giant squid" fishery vis-à-vis climate change and provided information for future fisheries management and conservation in the province.

A Collagen Basketweave from the Giant Squid Mantle as a Robust Scaffold for Tissue Engineering

The growing applications of tissue engineering technologies warrant the search and development of biocompatible materials with an appropriate strength and elastic moduli. Here, we have extensively studied a collagenous membrane (GSCM) separated from the mantle of the Giant squid Dosidicus Gigas in order to test its potential applicability in regenerative medicine. To establish the composition and structure of the studied material, we analyzed the GSCM by a variety of techniques, including amino acid analysis, SDS-PAGE, and FTIR. It has been shown that collagen is a main component of the GSCM. The morphology study by different microscopic techniques from nano- to microscale revealed a peculiar packing of collagen fibers forming laminae oriented at 60–90 degrees in respect to each other, which, in turn, formed layers with the thickness of several microns (a basketweave motif). The macro- and micromechanical studies showed high values of the Young’s modulus and tensile strength. No significant cytotoxicity of the studied material was found by the cytotoxicity assay. Thus, the GSCM consists of a reinforced collagen network, has high mechanical characteristics, and is non-toxic, which makes it a good candidate for the creation of a scaffold material for tissue engineering.

The Obligatory Underwater Level: Posthuman Genealogy of Amphibian Human in Media

Will humankind ever be able to live underwater? To answer this question from the perspective of visual media studies, I analyze narrative and expressive means used for positive representation of underwater experiences in several examples of screen media. My examples are principally different by origin and yet united by their highly enjoyable effect of immersion into underwater worlds. My primary focus is on Amphibian Man (1928), a cult early science fiction novel by Alexandr Belyaev adapted for screen in 1962 in the USSR.I also explore its unintentionally close contemporary reproduction in The Shape of Water (2016), which even led to accusations in plagiarism. The third example is a contemporary independent video game ABZU by Giant Squid (2016), which replays the same theme of amphibian human existence in a positive light. These cases present a surprisingly rare view of a safe, friendly and interactive marine world, approached by the protagonist who can breathe underwater. I apply the posthumanist lens to find out that, surprisingly, aquatic cyborgs seem to be underrated by the queer thought (Haraway, 2015, 2016); I conclude that the model of ‘queer ecologies’ may become the needed development.

Dead Zones in the Oceans

As this chapter shows, the open oceans are also running out of dissolved oxygen as seen at Station Papa in the subarctic Pacific Ocean, thanks to work done on Canadian weather ships starting in the 1950s. Not only are areas of severe hypoxia, or oxygen minimum zones, expanding, but the level of dissolved oxygen in all oceans is decreasing. The open oceans are losing oxygen because of climate change. The warming of the oceans reduces the solubility of oxygen in water and stimulates oxygen use by respiring organisms. This chapter explores how climate change is also altering circulation and the mixing of oxygen into oxygen-poor waters. Even where oxygen remains above dead-zone levels, its depletion is another sign of how climate change is reshaping the biosphere. The expansion of low-oxygen water has shifted the habitats of fish and invertebrates, such as the giant squid, over thousands of miles, and has disrupted the nitrogen cycle of the entire biosphere. The chapter explains that because of oxygen depletion, biological production of the oceans may decline due to the loss of nitrogen, while release of a potent greenhouse gas (nitrous oxide) may increase.

Mineral composition of raw and marinated-cooked arms from Pacific giant squid (Dosidicus gigas).

Background/aim: Shellfish consumption is often perceived as a potential health hazard due to the accumulation of toxic metals. The mineral content was investigated in marinated-cooked giant squid (Dosidicus gigas) arms from three Eastern Pacific fisheries (Peru, Chile and Benthic) to elucidate their contribution to daily recommended intakes and possible presence of pollutants. Material and methods: Thirty macro- and microminerals were analysed in the raw material, marination solution, cooking broth and cooked product. Results: Both raw and marinated-cooked squid arms contained nutritionally relevant quantities of essential macro- (Na and Mg) and microminerals (Cr, Zn, Mn and Se). Fishery origin led to minor variations in the mineral composition of raw arms, while marinated-cooked arms of Benthic origin had a higher retention of Na and juice likely due to their greater size. Levels of Pb, Hg, Zn or As found in the ready-to-eat product were below tolerable upper intake levels. Conclusion: The mineral content found in the raw squid arms suggests that the Pacific fisheries concerned are not affected by human polluting activities. Marinated-cooked squid arms cover a part of the dietary requirements for minerals and can be consumed without apparent negative nutritional implications.