Development of metal adaptation in a tropical marine zooplankton

Abstract

tropical marine ecosystems are highly vulnerable to pollution and climate change. it is relatively unknown how tropical species may develop an increased tolerance to these stressors and the cost of adaptations. We addressed these issues by exposing a keystone tropical marine copepod, Pseudodiaptomus annandalei, to copper (Cu) for 7 generations (F1-F7) during three treatments: control, Cu and pCu (the recovery treatment). In F7, we tested the "contaminant-induced climate change sensitivity" hypothesis (TICS) by exposing copepods to Cu and extreme temperature. We tracked fitness and productivity of all generations. In F1, Cu did not affect survival and grazing but decreased nauplii production. In F2-F4, male survival, grazing, and nauplii production were lower in Cu, but recovered in pCu, indicating transgenerational plasticity. Strikingly, in F5-F6 nauplii production of Cu-exposed females increased, and did not recover in pCu. The earlier result suggests an increased Cu tolerance while the latter result revealed its cost. In F7, extreme temperature resulted in more pronounced reductions in grazing, and nauplii production of Cu or pCu than in control, supporting TICS. The results suggest that widespread pollution in tropical regions may result in high vulnerability of species in these regions to climate change.

Direct and delayed synergistic effects of marine heatwaves, metals and food limitation on tropical reef-associated fish larvae

“…Thirdly, the delayed synergistic effects of contaminants, MHW and starvation lasted beyond the exposure period, which are critically important to understand how ecological memory (see Hughes et al, 2019; Jackson et al, 2021) can accelerate biodiversity loss in the tropics (Barlow et al, 2018; Darling and Côté, 2008; Hughes et al, 2019). Together with our previous studies on zooplankton (Dinh et al, 2020a; Dinh et al, 2021; Dinh et al, 2020b), the lethal effects of Cu on fish larvae occur at a concentration that is lower than the Cu concentration allowed for the coastal water of Vietnam, 200 µg Cu/L (QCVN-10-MT-2015-BTNMT, MONRE-Vietnam, 2015), which urgently asks for the updates in local and national regulations to protect the marine, particularly reef environment. This is especially important and urgent as reefs and, more generally, coastal marine ecosystems in the Southeast Asian countries are experiencing increasing levels of various anthropogenic pollutants (Dinh, 2019; Jambeck et al, 2015; Nguyen et al, 2020) and marine heatwaves (Yao et al, 2020).…”

“…The interaction of warming and contaminants has emerged as a central research theme in global change biology and ecotoxicology in the last decade (Crain et al, 2008; Dinh et al, 2020a; Dinh et al, 2021; Dinh et al, 2020b; Moe et al, 2013; Orr et al, 2020; Sokolova and Lannig, 2008). However, only a few studies have investigated whether an additional stressor, e.g., food limitation, competition, or predation stress, may further modify the interaction of warming and contaminants (Crain et al, 2008; Dinh et al, 2016a; Knillmann et al, 2013; Pham et al, 2020).…”

Changes in the Magnitude of the Individual and Combined Effects of Contaminants, Warming, and Predators on Tropical Cladocerans across 11 Generations

“…For example, offsprings of pesticide-exposed insects show higher vulnerability to pesticides, 23,24 yet the offsprings of Cu-exposed copepods show increased tolerance to Cu. 29 Assessing the interaction of anthropogenic contaminants, climate change, and biotic stressors such as predators, considering the contemporary evolutionary responses to these stressors across generations is novel, timely, and especially crucial to arriving at a more realistic ERA of multiple stressors. To address the above issues, we tested if elevated temperature and the presence of predator cues will increase the effects of lead (Pb) on life-history traits of a tropical cladoceran Moina dubia.…”

Agent Orange: Haft-Century Effects On The Vietnamese Wildlife Have Been Ignored

“… 8 Adaptations of Vietnamese invertebrates to long-term exposure to metals have recently been observed. 9 Evolutionary responses of surviving animals to Agent Orange can provide unique insights into physiological, epigenetic and genetic mechanisms underpinning the long-term effects of Agent Orange on the hyperdiverse tropical ecosystems such as sprayed forests, lakes, and rivers. Specimens can be sampled from various locations between sprayed (Ma Da Area) and nonspray regions (e.g., Cat Tien National Park) and analyzed to explore potential genetic changes.…”

“…Evolution of increased tolerance is likely after 50–60 years of exposure to Agent Orange substances, equivalents to several hundred to thousand generations of short-lived aquatic and soil invertebrates, for excample, cladocerans . Adaptations of Vietnamese invertebrates to long-term exposure to metals have recently been observed . Evolutionary responses of surviving animals to Agent Orange can provide unique insights into physiological, epigenetic and genetic mechanisms underpinning the long-term effects of Agent Orange on the hyperdiverse tropical ecosystems such as sprayed forests, lakes, and rivers.…”