Ron O'Dor

Biodiversity's Big Wet Secret: The Global Distribution of Marine Biological Records Reveals Chronic Under-Exploration of the Deep Pelagic Ocean

Background Understanding the distribution of marine biodiversity is a crucial first step towards the effective and sustainable management of marine ecosystems. Recent efforts to collate location records from marine surveys enable us to assemble a global picture of recorded marine biodiversity. They also effectively highlight gaps in our knowledge of particular marine regions. In particular, the deep pelagic ocean – the largest biome on Earth – is chronically under-represented in global databases of marine biodiversity. Methodology/Principal Findings We use data from the Ocean Biogeographic Information System to plot the position in the water column of ca 7 million records of marine species occurrences. Records from relatively shallow waters dominate this global picture of recorded marine biodiversity. In addition, standardising the number of records from regions of the ocean differing in depth reveals that regardless of ocean depth, most records come either from surface waters or the sea bed. Midwater biodiversity is drastically under-represented. Conclusions/Significance The deep pelagic ocean is the largest habitat by volume on Earth, yet it remains biodiversitys big wet secret, as it is hugely under-represented in global databases of marine biological records. Given both its value in the provision of a range of ecosystem services, and its vulnerability to threats including overfishing and climate change, there is a pressing need to increase our knowledge of Earths largest ecosystem.

The nutritional value of dietary n-3 and n-6 fatty acids for the Chinese prawn (Penaeus chinensis)

Abstract Triacylglycerides of highly purified n -3 and n -6 fatty acids (18:2 n -6, 18:3 n -3, 20:4 n -6 and 22:6 n -3) were each added separately at 1% to a basal diet which contained 4% of an equal mixture of tripalmitin and triolein to make four experimental diets with a control diet which contained 5% of the 16:0 and 18:1 n −9 mixture as the only lipid. Each diet was fed to replicate groups of juvenile Chinese prawn ( Penaeus chinensis ) for 32 days. The prawn fed the control diet without supplemental n -6 or n -3 fatty acids showed poor growth and survival. The addition of 1% of 18:2 n -6, 18:3 n -3 or 20:4 n -6 to the basal diet significantly improved weight gains ( P n -3 or 20:4 n -6 also significantly improved survival rate and molting frequency. The prawn fed the diet containing 1% 22:6 n -3, however, exhibited the highest survival rate, molting frequency and weight gain among the five diets ( P n -6 and n -3 fatty acids have essential fatty acid (EFA) value to the Chinese prawn, and that the EFA value increases in the order 18:2 n -6 n -3≤20:4 n -6 n -3.

Squid (Loligo forbesi) performance and metabolic rates in nature

Squid are the fastest swimming invertebrates, but the metabolic cost of speed, as assessed in swim‐tunnels, is several‐fold higher than in fish, making squid appear uncompetitive. Because oxygen consumption can be correlated with jet pressure, it is possible to monitor pressure and thus estimate performance and energy costs in nature. Tracking in course and depth gave a 3‐D view of squid (Loligo forbesi) activities and costs for nearly three animal‐weeks; five days of this included telemetry of jet pressures. These 2–5 kg loliginids hovered off‐bottom most of the time, perhaps to avoid predation or damage to delicate skins. Hovering consumes about 50 ml O2 kg‐1 h‐1, twice as much as resting on bottom and half of overall average costs. Jet pressures were not well correlated with horizontal movements or tidal cycles, suggesting squid may “soar”; to reduce the cost of remaining in active current areas, acting as sit‐and‐wait predators. Maximal aerobic jetting was rare and usually associated with vertical cli...

Big squid in big currents

A link is proposed between the processes that led to the evolution of large species of squid and the highly variable, cyclic recruitment seen in squid fisheries. Maximum growth requires maximal feeding and minimal routine metabolism at optimum temperatures, which decrease as squid grow. Topographically induced upwelling zones, inshore of western boundary currents, provide productive environments with appropriate temperatures for all life stages. Most squid are small and live in the tropics or subtropics; locomotor constraints prevent them from swimming long distances. Long annual migrations to spawn upstream in current systems require short-lived squids to maximize rates of growth. Therefore, such systems provide the opportunity and a powerful selective advantage for large size and rapid growth. Increased fecundity and cannibalism provide additional directional selection for large individuals. Current systems show food production peaks (blooms); paralarval release must match these to increase survival. Be...

Oxygen uptake and nitrogen excretion in two cephalopods, octopus and squid

Abstract 1. 1. During exercise of the squid Illex illecebrosus swimming up to 3 body lengths/sec, resting values at 15°C for both oxygen uptake (11.3 mM O2/kg per hr) and ammonium excretion (1.4 mM NH4/kg per hr) increased about five-fold; both parameters were always correlated with an excretory O:N ratio of 15. 2. 2. In Octopus, both oxygen uptake and ammonium excretion rates at rest were about five-fold lower than in Illex. 3. 3. Urea was 30% of the measured nitrogen excretion in Octopus and 24% in Illex at rest, respectively. 4. 4. During swimming, urea excretion in Illex was irregular and not correlated with ammonium excretion. 5. 5. Glutamic dehydrogenase activity with a significant capability for glutamate oxidation (0.3–3.1 Units/g tissue; 25°C) as well as adenosine deaminase activity (0.4–3.3 units/g tissue) were found in several Illex tissues.

The effect of different dietary energy levels in crab-protein-based diets on digestibility, oxygen consumption, and ammonia excretion of bilaterally eyestalk-ablated and intact juvenile lobsters, Homarus americanus

Abstract The fast growth resulting from eyestalk ablation of juvenile lobsters, Homarus americanus , can be attributed to more efficient energy utilization as indicated by lower feeding metabolism, particularly the calorigenic effect of feeding and lower nitrogen excretion than found for intact lobsters. However, there was no difference in standard metabolism between ablated and intact juvenile lobsters. The apparent digestibility of dry matter by ablated lobsters was lower than intact controls when fed low energy (high protein energy ratio) and/or high α-cellulose diets. The apparent lipid digestibility was reduced by eyestalk ablation, whereas there was no effect of ablation on apparent protein digestibility. The apparent digestibilities of dry matter and energy improved with increased dietary energy and/or decreased α-cellulose levels in both ablated and intact lobsters. However, while apparent digestibilities of protein and lipid also increased with dietary energy in ablated lobsters, for intact lobsters the apparent digestibility of protein was relatively constant and apparent digestibility of lipid reached a peak at intermediate levels of dietary energy. The dependence on protein for energy utilization may be greater for ablated lobsters. The energy budget equation of lobsters constructed from the data obtained in this study will be very useful for understanding energy utilization of lobsters.

A Census of Fishes and Everything They Eat: How the Census of Marine Life Advanced Fisheries Science

ABSTRACT The Census of Marine Life was a 10-year, international research effort to explore poorly known ocean habitats and conduct large-scale experimentation with new technology. The goal of Census 2010 in its mission statement was to describe what did live in the oceans, what does live in the oceans, and what will live in the ocean. Many of the findings and techniques from census research may prove valuable in making a transition, which many governments have publicly endorsed, from single-species fisheries management to more holistic ecosystem management. Census researchers sampled continental margins, mid-Atlantic ridges, ocean floor vents and seeps, and abyssal plains and polar seas and organized massive amounts of past and new information in a public online database called the Ocean Biogeographic Information System (www.iobis.org). The census described and categorized seamount biology worldwide for its vulnerability to fishing, advanced large-scale animal tracking with acoustic arrays and satellite a...

Advancing “bio” sensor integration with Ocean Observing Systems to support ecosystem based approaches

The vision of the US Integrated Ocean Observing System (U.S. IOOS) is to provide information and services to the nation for enhancing our understanding of the ecosystem and climate; sustaining living marine resources; improving public health and safety; reducing impacts of natural hazards and environmental changes; and expanding support for marine commerce and transportation. In the last decade U.S. IOOS has made considerable progress in advancing physical and chemical observing systems, but only modest progress integrating biological observations from disparate data providers, and there remain challenges to fully integrate biological observing systems into U.S. IOOS. Recent technological advances in miniature, low power “bio” sensor can record everything from plankton greater than 20 micrometer with electro-optical technology, to hydroacoustic sensors that can record meso-zooplankton and nekton from mobile autonomous platforms, to satellite linked recorders that can record the movement and behavior of the largest marine predators. This opens up remarkable opportunities for observing the biotic realm at critical spatio-temporal scales that are most relevant to organisms, which have been out of reach until present. “bio”sensor technology is mature and proven to be operational and biological monitoring should be an integrated component of observing systems. Optimally, it should be clearly defined and implemented in close association with physical oceanographers. The integration of biological observing into U.S IOOS will only strengthen the national observing capabilities to respond to the growing needs for ecosystem observation to support ecosystem-based approaches and sustain our living marine resources.

Interpreting behavioural data from Radio-Acoustic Positioning Telemetry (RAPT) systems

To detect behavioural patterns of individually tagged squid Loligo vulgaris reynaudii in a Radio-Acoustic Positioning Telemetry (RAPT) buoy array, trajectories reflecting the four dimensions of latitude, longitude, depth and time were plotted from data collected during field experiments in South Africa. Finding a continuous curve to represent the sampled trajectories required dealing with anisotropic precision and accuracy, non-uniform sampling rates and improbable outliers. A combination of an operator-controlled smoothing option of an approximating cubic spline and a weight factor assignment based on distance from the mass curve gave the most expedient results when compared with video recordings.

Detecting trajectories of change in marine ecosystems: Biotic indicators for observing systems

Federal, regional, state, territorial, tribal, and local aquatic resource review processes have all moved towards implementation of Ecosystem-Based Management (EBM). This provides an opportunity to improve ocean, coastal, and Great Lakes stewardship versus continuing with a fragmented, sector-specific process that only looks at individual components of or influences on an ecosystem. To accomplish this goal, EBM requires integrated ecosystem assessments. These assessments require observing data that reflect the pressures and responses that are of concern to managers. Monitoring and indicators of the physical aspects of marine systems are well developed, as is the development and application of models for the physical features of marine ecosystems. Although extant and monitored, relative to physical features, indicators of marine habitat and the biota need to be better integrated with Ocean Observing Systems. This will ensure sufficient monitoring to detect critical changes in marine ecosystems. Here we review a suite of such ecosystem indicators to measure change in the biological properties of marine ecosystems. From that, we provide recommendations for their integration within the US Integrated Ocean Observing System (U.S IOOS).