Ecological Niches and Geographic Distributions of Lanternfishes

Lanternfishes (Myctophidae) dominate fish diversity and biomass within the mesopelagic ocean between 200-1000m deep. In the face of exploitation and climate change there is a need to predict their current and future biogeography as well as the ecological and evolutionary mechanisms responsible for these patterns. This thesis aimed to fill this gap by using Ecological Niche Models (ENMs) to estimate species’ fundamental niches and associated distributions. With a focus on Southern Ocean species, uncertainties were investigated regarding (i) the application of ENMs to a 3-dimensional environment by comparing ‘3D’ and ‘2D’ approaches, and (ii) the use of climate data when projecting ecological responses to climate change by undertaking a literature review and using Electrona antarctica to reveal the variability in projections that can result from multiple levels of climate uncertainty. These results were then used to predict the current and future distribution of ten lanternfish species using a ‘2D’ ENM and an ensemble of climate change simulations. Species showed high affiliation to water masses and contrasting future responses. Antarctic species with restricted thermal niches and available habitat in which to disperse were most vulnerable to climate change which has implications for the size structure of the myctophid community and wider consequences for predators and prey. The global phylogeography of lanternfishes was investigated to elucidate the mode and mechanisms of speciation. Species grouped in to broad biogeographic clusters with recently diverged species displaying highest spatial overlap. The niche, depth, and photophore patterns analysed gave no clear indication of the mechanisms facilitating speciation, but there is strong evidence that sympatric or parapatric speciation is a dominant mode of divergence. Overall, these findings demonstrate that the unique physical and environmental setting of the vast pelagic ocean has played, and will continue to play, an important role in the biogeography and diversification of lanternfishes

A Content Analysis of News Source Characteristics Within Broadcast News Stories Concerning the Financial Crisis Between September 8, 2008 – December 31, 2008

A content analysis was conducted to identify potential differences in the characteristics of sources appearing in stories shown on the three national evening news broadcasts of ABC World News, CBS Evening News, and NBC Nightly News during the first four months of the 2008 Financial Crisis. The names, titles, affiliations, and societal sectors of each on-camera, named individual were identified and analyzed for their differences and frequencies of appearance. The study found the government sector was the most frequently appearing sector, and members of the House of Representatives appeared far more than any other government officials. Though the evening network news shows are structured similarly and cover the same major stories each night, there are differences in who they call upon to provide facts, analysis, and insight

DVM: The World’s Biggest Game of Hide-and-Seek

Diel vertical migration (DVM) refers to the daily, synchronized movement of marine animals between the surface and deep layers of the open ocean. This behavior is the largest animal migration on the planet and is undertaken every single day by trillions of animals in every ocean. Like a big game of hide-and-seek, animals that perform DVM spend the day hiding from predators in the deep ocean, and then migrate to the surface to feed under the cover of darkness. In this article we will explore this incredible strategy for survival. We will introduce the animals involved, describe how the environment of the open ocean drives DVM, and reveal the questions still to be answered as the ocean environment continues to change

5 things to know about generative text AI tools... that might be outdated or upgraded by the time of publication

This brief newsletter article describes how academic librarians can begin learning about and using generative text AI tools such as ChatGPT.</p

Assessing key influences on the distribution and life-history of Arctic and boreal Calanus: are online databases up to the challenge?

Despite the importance of calanoid copepods to healthy ecosystem functioning of the Arctic Ocean and Subarctic Seas, many aspects of their biogeography, particularly in winter months, remain unresolved. At the same time, online databases that digitize species distribution records are growing in popularity as a tool to investigate ecological patterns at macro scales. The value of such databases for Calanus research requires investigation - the long history of Calanus sampling holds promise for such databases, while conditions at high latitudes may impose limits through spatial and temporal biases. We collated records of three Calanus species (C. finmarchicus, C. glacialis, and C. hyperboreus) from the Ocean Biodiversity Information System (OBIS) and the Global Biodiversity Information Facility (GBIF) providing over 230,000 unique records spanning 150 years and over 100 individual datasets. After quality control and cleaning, the latitudinal and vertical distribution of occurrences were explored, as well as the completeness of informative metadata fields. Calanus sampling was found to be temporally and spatially biased towards surfacemost layers (&lt;10m) in spring and summer. Only 3.5% of records had an average collection depth ≥400m, approximately half of these in months important for diapause. Just over 40% of records lacked associated information on sampling protocol while 11% of records lacked life-stage information. OBIS data contained fields for maximum and minimum collection depth and so were subset into discrete “shallow summer” and “deep winter” life cycle phases and matched to sea-ice and temperature conditions. 23% of OBIS records north of 66° latitude were located in regions of seasonal sea-ice presence and occurrences show species-specific thermal optima during the shallow summer period. The collection depth of C. finmarchicus was significantly different to C. hyperboreus during the deep winter. Overall, online databases contain a vast number of Calanus records but sampling biases should be acknowledged when they are used to investigate patterns of biogeography. We advocate efforts to integrate additional data sources within online portals. Particular gaps to be filled by existing or future collections are (i) widening the spatial extent of sampling during spring/summer months, (ii) increasing the frequency of sampling during winter, particularly at depths below 400m, and (iii) improving the quality, quantity and consistency of metadata reporting

The feminine matriarchal in the Marisa Madieri’s narrative

This paper examines and interprets the narrative of the Italian woman writer Marisa Madieri as a rediscovering of the matriarchal female. The building of a genealogy represents a constant element within her writings. Many of these are the female archetypes directed linked to the Great Mother or Great Godness myth. In addition, there are many female metaphors that are related to the generative force and references to female mythological figures and female symbols

Future Distribution of Suitable Habitat for Pelagic Sharks in Australia Under Climate Change Models.

Global oceans are absorbing over 90% of the heat trapped in our atmosphere due to accumulated anthropogenic greenhouse gases, resulting in increasing ocean temperatures. Such changes may influence marine ectotherms, such as sharks, as their body temperature concurrently increases toward their upper thermal limits. Sharks are high trophic level predators that play a key role in the regulation of ecosystem structure and health. Because many sharks are already threatened, it is especially important to understand the impact of climate change on these species. We used shark occurrence records collected by commercial fisheries within the Australian continental Exclusive Economic Zone (EEZ) to predict changes in future (2050-2099) relative to current (1956-2005) habitat suitability for pelagic sharks based on an ensemble of climate models and emission scenarios. Our predictive models indicate that future sea temperatures are likely to shift the location of suitable shark habitat within the Australian EEZ. On average, suitable habitat is predicted to decrease within the EEZ for requiem and increase for mackerel sharks, however, the direction and severity of change was highly influenced by the choice of climate model. Our results indicate the need to consider climate change scenarios as part of future shark management and suggest that more broad -scale studies are needed for these pelagic species

Climate change drives poleward increases and equatorward declines in marine species

Marine environments have increased in temperature by an average of 1°C since preindustrial (1850) times [1]. Given that species ranges are closely allied to physiological thermal tolerances in marine organisms [2], it may therefore be expected that ocean warming would lead to abundance increases at poleward range edges, and abundance declines towards the equator [3]. Here we report a global analysis of abundance tends of 304 widely distributed marine species over the last century, across a range of taxonomic groups from phytoplankton to fish and marine mammals. Specifically, using a literature database we investigate the extent that the direction and strength of longterm species abundance changes depend on the sampled location within the latitudinal range of species. Our results show that abundance increases have been most prominent where sampling has taken place at the poleward edges of species ranges, while abundance declines have been most prominent where sampling has taken place at the equatorward edge of species ranges. These data provide evidence of omnipresent large-scale changes in abundance of marine species consistent with warming over the last century, and suggest that adaptation has not provided a buffer against the negative effects of warmer conditions at the equatorward extent of species ranges. On the basis of these results we suggest that projected sea temperature increases of up to 1.5°C over pre-industrial levels by 2050 [4] will continue to drive latitudinal abundance shifts in marine species, including those of importance for coastal livelihoods

Illuminating the Living Lanterns of Antarctica

Lanternfish are a relatively small but very abundant fish. They live deep in the ocean’s “twilight” zone where there is not much light. A unique community of lanternfish live in the Southern Ocean, where they are a key part of the Antarctic food web. Lanternfish also play an important role in moving carbon from the atmosphere into the deep ocean, where it is stored. In this article, we explain current knowledge on Southern Ocean lanternfish, including how they produce their own light! We will also tell you about some mysteries surrounding lanternfish that scientists are yet to solve