Christine L. Huffard

Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean

Significance Global warming is now a well-documented phenomenon that is influencing every aspect of our world, from increased storm intensity to melting of polar ice sheets and rising sea level. The impact of such changes in climate is least known for the deep ocean, which covers over 60% of the earth’s surface. An unprecedented 24-y time series measuring changes in food supply and utilization by benthic communities at 4,000-m depth in the deep northeast Pacific reveal strong connectivity with changing surface ocean conditions, which have broad implications for the global carbon cycle. The deep ocean, covering a vast expanse of the globe, relies almost exclusively on a food supply originating from primary production in surface waters. With well-documented warming of oceanic surface waters and conflicting reports of increasing and decreasing primary production trends, questions persist about how such changes impact deep ocean communities. A 24-y time-series study of sinking particulate organic carbon (food) supply and its utilization by the benthic community was conducted in the abyssal northeast Pacific (∼4,000-m depth). Here we show that previous findings of food deficits are now punctuated by large episodic surpluses of particulate organic carbon reaching the sea floor, which meet utilization. Changing surface ocean conditions are translated to the deep ocean, where decadal peaks in supply, remineralization, and sequestration of organic carbon have broad implications for global carbon budget projections.

Individually Unique Body Color Patterns in Octopus ( Wunderpus photogenicus ) Allow for Photoidentification

Studies on the longevity and migration patterns of wild animals rely heavily on the ability to track individual adults. Non-extractive sampling methods are particularly important when monitoring animals that are commercially important to ecotourism, and/or are rare. The use of unique body patterns to recognize and track individual vertebrates is well-established, but not common in ecological studies of invertebrates. Here we provide a method for identifying individual Wunderpus photogenicus using unique body color patterns. This charismatic tropical octopus is commercially important to the underwater photography, dive tourism, and home aquarium trades, but is yet to be monitored in the wild. Among the adults examined closely, the configurations of fixed white markings on the dorsal mantle were found to be unique. In two animals kept in aquaria, these fixed markings were found not to change over time. We believe another individual was photographed twice in the wild, two months apart. When presented with multiple images of W. photogenicus, volunteer observers reliably matched photographs of the same individuals. Given the popularity of W. photogenicus among underwater photographers, and the ease with which volunteers can correctly identify individuals, photo-identification appears to be a practical means to monitor individuals in the wild.

Inking in a Blue-Ringed Octopus, Hapalochlaena lunulata, with a Vestigial Ink Sac

Here we report for the first time that adult Hapalochlaena lunulata (Quoy & Gaimard, 1832), which has a vestigial ink sac, is capable of inking. Ink was released under three different agonistic conditions: female-female aggression, rejection of mating attempt, and when attacked by a predator. We observed no apparent reaction to the ink by the other animals involved in these interactions.

Wild Wunderpus photogenicus and Octopus cyanea employ asphyxiating ‘constricting’ in interactions with other octopuses

Aggressive constricting including asphyxiation was observed in wild octopuses (Octopus cyanea Gray, 1849, and Wunderpus photogenicus Hochberg, Norman & Finn, 2006). The distal portion of a dorsolateral arm formed a loop around the mantle of another octopus, in at least one case preventing the flow of water into the mantle, over the gills and out of the funnel. Constricting also may have prevented the subordinate individual from releasing ink, a possible irritant and predator attractant. A female O. cyanea used constricting as a form of fatal aggression to asphyxiate a male as part of apparent sexual cannibalism. This female killed a male with which she was mating using the ‘distance’ position. Constriction allowed a W. photogenicus to win during physical interspecific aggression with a close relative, Thaumoctopus mimicus Norman & Hochberg, 2005. This action took place near an immediately available food source and interrupted foraging by T. mimicus, providing possible evidence of interference competition among closely related sympatric cephalopod species in the wild.