Question

Given what you know at this point about marine iguanas and the abiotic effects of enso, develop two possible directions of research that liz should pursue to understand exactly why the iguanas suffered such a high mortality. keep in mind that you need to consider indirect effects. while environmental temperature does change metabolic rates of ectotherms, the iguanas are exposed to a wide range of temperatures as they feed and bask on the lava. direct mortality in response to a temperature change of a couple of degrees is unlikely.

Answer 1

Research into the high mortality of marine iguanas due to ENSO could focus on the effects of climate change on their marine ecosystem and food sources, as well as increased predation from non-native species introduced to the Galápagos Islands.

Step-by-step explanation:

To understand why marine iguanas suffered a high mortality rate due to the abiotic effects of ENSO (El Niño Southern Oscillation), there are two possible research directions that could be pursued. Firstly, it is crucial to explore the impact of climate change on marine ecosystems, particularly how rapid temperature increases can cause species to become extinct before they have a chance to adapt. This includes examining how the iguanas' primary food sources are affected by increased sea temperatures and whether this leads to nutritional deficits.

Secondly, research should be conducted on the predatory pressures from non-native species, such as dogs and cats, which have been introduced to the Galápagos Islands and pose a threat to the iguanas. Understanding the increase in predation risk, combined with the stresses from ENSO, could explain the heightened mortality rates. This research would benefit from studies on the behavior and population dynamics of both the iguanas and their introduced predators during and after ENSO events.

Answer 2

Since understand that temperature change is unlikely to be the cause of the high mortality rate in marine iguanas, other factors must be considered. In recent years, pollution in the waters has increased due to oil spills and the like, which has a devastating impact on all wild life, including marine iguanas. Another theory is the ever encroaching human presence, as we expand our cities taking up more and more of what use to be livable regions for such animals.