Lots in the press over that last week, with the start of the publication of a new PLoS 1 collection on marine biodiversity, one of the outcomes of the Census of Marine Life (2000-2010). In the conservation field we have encouraging support for marine reserves from US studies, though there is strong indication that multi-use reserves are not as efffective as might be hoped – strongly policed no-take zones are really the only option for allowing the recovery of many areas. Otherwise, we have a number of publications on hard corals – some good basic science for a change in ‘Life at Sea’, plus a look at how well corals establish at higher temperatures in our climate change section.

Marine biodiversity and biogeography: The release of a collection of articles from around the world, each article describes the physical, geological, chemical, and biological characteristics of a region of the worlds oceans. Current papers cover the Pacific, Mediterranean, Caribbean, Antarctic, a US overview, and South Africa. These publications follow on from a decade of work by the Census of Marine Life, that attempted to bring together a corpus of knowledge about the biodiversity of our oceans.
PLoS ONE: Marine Biodiversity and Biogeography – Regional Comparisons of Global Issues

Life at Sea

Video of nudibranch out to lunch: Out on the beach on Wednesday we were lucky enough to see a few nudibranchs close to the low-water mark. To get a better idea of how they look underwater without diving, try this video link – Via Deep sea News, via Fish and Aquatic News.

Blue whales find mates by Doppler shift: Recent evidence suggests that blue whale song is so precise in frequency that they could, in principle, detect whether or not a potential mate is swimming towards or away from them by the doppler shift of its song. ScienceDaily (Aug. 2, 2010)

Spongy sequence: The complete genome of the sponge Amphimedon queenslandica has just been sequenced. Sponges are probably the simplest multicellular animals on the planet – and represent an important step in evolution, moving away from a single-celled body plan seen in the protozoa, to the types of animal we are more familiar with. In making this change cells have to learn to live together – growing only where they are wanted – so the sponge may provide a simple model for the basic diseases of all multicellular organisms – such as cancer. ScienceDaily (Aug. 5, 2010)

Krill prefer the shallows: Small research vessels have carried out krill (Euphausia superba) surveys in the shallow waters of antarctica, and found the biomass to be very much greater there than in the deeper water, where previous larger survey vessels had been able to work. ScienceDaily (Aug. 5, 2010)

Mobile bacteria hitch a ride: While the ocean looks homogeneous, it is composed of many distinct bodies of water with different temperatures and salinities, and mixing at the boundaries between these bodies is very slow. As a consequence organisms like bacteria, that rely on water movement to get about, should find it very difficult to pass from one water body to another. In practice, however, scientists have found that they can hitch a ride on zooplankton. Many species of zooplankton commute every evening from cold, deep water, into warmer surface waters to prey on phytoplankton. We now know that this migration is an important transport mechanism for bacteria as well. ScienceDaily (Aug. 10, 2010)

Modern corals give up sex: Most anemones (class Anthazoa) have separate sexes, but the hard corals (Scleratinia) are almost exclusively hermaphrodite. This paper indicates that not only are they anomalous, they have evolved a hermaphroditic sex life no fewer than three times! The implication is that being a hermaphrodite has significant advantages if you are a coral…
(From abstract only:) A. M. Kerr, A.H. Baird and T.P. Hughes Correlated evolution of sex and reproductive mode in corals (Anthozoa: Scleractinia). Proc. Roy. Soc. B. doi: 10.1098/rspb.2010.1196

They come from the deep? There have been a lot of problems in working out the family tree of the hard corals (order: scleratinia). The accessible shallow water reef-forming corals occur in a multitude of morphologies, and even genetic analysis has not been able to work out how they relate to each other. In this paper the genetic study has been extended to the deep water solitary corals (similar to the devonshire cup coral, Caryophillia smithii, which is common in UK waters), and suggests that these might hold the key to unlocking the evolution of these iconic organisms.
Kitahara MV, Cairns SD, Stolarski J, Blair D, Miller DJ (2010) A Comprehensive Phylogenetic Analysis of the Scleractinia (Cnidaria, Anthozoa) Based on Mitochondrial CO1 Sequence Data. PLoS ONE 5(7): e11490. doi:10.1371/journal.pone.0011490

Stay at home isopods: Isopods are probably the commonest encountered crustacea – the woodlouse being a typical member of the group. Species in the genus Ligia (‘sea slaters’) live in between rocks and pebbles on suitable shores all around the world. Like the woodlouse, however, they are almost totally adapted to living on dry land, and won’t enter the water other than by accident or to excape a predator – though possessing gills they are capable of surviving indefinitely in this medium. They don’t have a planktonic larval stage, so the dispersion of the genus is prety much restricted to how far they can walk…
As a consequence, it is a bit of a mystery as to how they have become so ubiquitous, one species Ligia exotica, is thought to have been introduced around the world by maritime traffic. This paper, however, indicates that there is a great deal of genetic variation between populations even of exotica, whilst the genetics of other species in the genus reflect geological events, with very slow gene-flows between neighbouring populations. The genus is, therefore, home to a number of cryptic species – ones that look identical, but are genetically quite distinct. The reason why they retain their distinctive morphologies inspite of underlying genetic change is not clear – perhaps they are physically just very well adapted to thier environment!
Hurtado LA, Mateos M, Santamaria CA (2010) Phylogeography of Supralittoral Rocky Intertidal Ligia Isopods in the Pacific Region from Central California to Central Mexico. PLoS ONE 5(7): e11633. doi:10.1371/journal.pone.0011633

Sexy anemones: Fortunate divers will have seen large displays of sea anemones all of a single colour – almost certainly these are derived by cloning of a single individual to fill the space available. Anemones are also capable of sexual reproduction, however, releasing gametes into the water, where they are fertilised by accident. This paper examines the sexual behaviour of Aiptasia diaphana, which shows a preference for asexual reproduction (cloning) in the warm months of summer. They estimate that a founding individual (genet) can bud off up to 5000 clones (ramets) in a single year! The clones that are produced, however, can be either male of female, though they seem to be squed in favour of the sex of the founding genet. Sexual reproduction by spawning is timed by both temperature and day-length to maximise the chance of fertilisation (some cnidaria have very specific dates on which they spawn). This report is from the US, Aiptasia diaphana does not occur in UK waters, though it has been reported in the Mediterranean (ERMS (2009). Aiptasia diaphana (Rapp, 1829). Accessed through: Costello, M.J.; Bouchet, P.; Boxshall, G.; Arvantidis, C.; Appeltans, W. (2009) European Register of Marine Species at http://www.marbef.org/data/aphia.php?p=taxdetails&id=100858 on 2010-07-30).
Schlesinger A, Kramarsky-Winter E, Rosenfeld H, Armoza-Zvoloni R, Loya Y (2010) Sexual Plasticity and Self-Fertilization in the Sea Anemone Aiptasia diaphana. PLoS ONE 5(7): e11874. doi:10.1371/journal.pone.0011874

How seabirds cope with changes in prey availability: Black noddys (Anous minutus) were observed to cope badly with reduced prey availability associated with anomalously high surface water temperatures in this Australian study.
Devney CA, Caley MJ, Congdon BC (2010) Plasticity of Noddy Parents and Offspring to Sea-Surface Temperature Anomalies. PLoS ONE 5(7): e11891. doi:10.1371/journal.pone.0011891

Conservation

NOAA finds that US National Marine Sanctuary System works: The US has 14 marine protected areas covering about 150,000 square miles of ocean. They operate on the principle of ‘ecosystem management’ – looking at the ecosystem as a whole, and the different pressures put upon it by commercial and recreational usage and pollution. There is a link to the full NOAA report in this article, see also following report on the Stellwagen Sanctuary. ScienceDaily (Aug. 2, 2010)
THe US sanctuaries appear similar to the proposed Conservation Zones, which are not no-take marine reserves, but are to be managed with input from all stake-holders. The problem that has occurred with systems of this sort in the past is that in the past management has been dominated by commercial interests, and has eventually resulted even in the destruction of the resource of interest to the industry concerned. https://lancashiremcs.org.uk/blog/2010/07/30/fisheries-collapse-in-the-firth-of-clyde/

Biodiversity under pressure: Numbers of top predators such as halibut and swordfish have declined over the last century at the Stellwagen Bank National Marine Sanctuary. Commercial catch levels are also down, as is the biodiversity of benthic fauna. The area has been a designated sanctuary since 1992. ScienceDaily (Aug. 2, 2010).
Again, we have to ask whether or not the marine ecosystem is now under so much stress that we really do need very large area no-take zones to offer it any chance of recovery…

Pollution

Where has all the oil gone? The Us’ National Oceanic and Atmospheric Administration (NOAA) and the Department of the Interior (DOI) have jointly worked out an ‘oil budget’, to calculate what has happened to the estimated 4.9 million barrels of oil released from the Deepwater Horizon.

• 33% of the total was collected (20%), chemically dispersed (8%) or burnt (5%).
• 25% evaporated or dissolved.
• 16% was naturally dispersed as microscopic droplets in the water column.
• 26% is residual – either on the water surface, or washed ashore, or burried in sediment.

What this report really says is that 75% of the material has been left to the natural ecosystem to deal with – in the form of dispersed oil, fumes, slick or tar balls. Only a small proportion (8%) was chemically dispersed – so does this process make sense given that it may increase damage to the environment? ScienceDaily (Aug. 8, 2010)

Bioremediation: A bacterial bioremediation solution developed at Tel Aviv University has been applied to clean out the bilges of oil tankers at sea and is used around the world for this purpose. Scientists have also shown it to be effective for cleaning up residual oil in sediments. ScienceDaily (Aug. 4, 2010)

Commentary – buying expert advice: A lot of research is commecrially funded, but how does this impact the impartiality of the expert advice available to you? In the case of the Gulf Oil Spill, BP is accused of attempting to buy consultancy services from entire Marine research labs – the proviso for receiving funding is that any material BP is unhappy with must be kept under a publication ban for three years. This is, by comparison with some research funding deals, quite a mild restraint. Deep-Sea News August 1st 2010.

Climate change

Sick oceans: Increased CO₂ levels and reduced oxygen levels are the outcomes of our addiction to fossil fuels. These changes are likely to put a lot of organisms under stress, but fish, oysters, crabs and shrimp have now all been shown to suffer impaired immune defence far worse than anything expected from small changes in gas concentrations. ScienceDaily (Aug. 5, 2010)

Ice-free waters will not mop up CO₂: Research indicates that the capacity of an ice-free arctic ocean for absorbing CO₂ is very small. Previous climate change models had assumed that the extra area of ice-free water would be highly productive, and so help to remove excess carbon dioxide from the atmosphere, so limiting further damage. This previous model had been calibrated by looking at the highly productive waters found at the margins of the modern ice sheet. The new figures are calculated based on looking at the effect of increased CO₂ concentration on phytoplankton growth rates. As many phytoplankton have calcareous exoskeletons, the increased acidity caused by the carbon dioxide makes it harder for them to grow. ScienceDaily (Aug. 2, 2010)

Can corals adapt to warmer temperatures? Coral bleaching and mortality has been witnessed with increased frequency in recent years, in response to elevated surface water temperatures. Most climate warming scenarios predict that these high-temperature events will become more frequent, leading to increased damage to existing reef systems. This paper examines whether or not the hard coral Montastraea faveolata can survive higher temperatures if exposed to these in early life. The work indicates that this species is able to adapt to elevated temperatures, unusually this does not appear to involve increased production of heat shock protein (HSP), but the expected up-regulation of oxidation stress genes does occur. While young corals do appear to be able to adapt, it is not clear that established reefs will be able to do this.
Polato NR, Voolstra CR, Schnetzer J, DeSalvo MK, Randall CJ, et al. (2010) Location-Specific Responses to Thermal Stress in Larvae of the Reef-Building Coral Montastraea faveolata. PLoS ONE 5(6): e11221. doi:10.1371/journal.pone.0011221