After Pliny’s monstrosity, many centuries went by before this question was really tackled again.  In 1815, Edward Forbes took a ride aboard the HMS Beacon, where he dredged the bottom at depths from 1-1,380 feet (0 – 420 m).  Just so you know, the average depth of the ocean is about 12,000 feet (4,000 m).  So, when I say he was barely scratching the surface, I’m not really exaggerating.  But nevertheless, he dredged the depths that he did and found that the deeper he dredged at, the less things he found.  So naturally, he thought, there must be a “zero point” at which no animals live.  He wildly extrapolated his data and determined that below 1,800 feet (600 m) there exist no animals, and he called this the “azoic zone.” So, Forbes’ answer to how many species in the deep sea was a big fat “not many.”

Luckily this “azoic zone” nonsense only lasted about 50 years.  In 1869, Charles Wyville Thomson and the rest of the crew onboard the HMS Porcupine pulled up animals from 14,610 feet (4,450 m) deep in the waters south of Ireland.  These results were later confirmed by the Challenger expedition which found animals at all depths, all over the globe.  This undeniably proved there was life at all depth of the oceans- but the question still remained.  How many species in the deep sea?

Fast forward to 1992.  Frederick Grassle and Nancy Maciolek conduct a massive (for the time) survey of the tiny animals that live in the sediments in the deep sea.  These are not the cute crawlies that live on top of the mud that had been previously sampled with dredges.  These are the small animals that live their lives between the grains of dirt at the bottom of the ocean.  Of the 798 species that they found, over half were new to science!  Pliny’s head would explode if he heard that more than double the total animals he thought existed in the whole ocean were found just in the mud.

Grassle and Maciolek did some impressive math and ended up calculating that they were finding one new species per square kilometer they sampled.  Let’s break that down.  One square kilometer is equal to a little more than one-third of a square mile.  So, they are basically finding three new species in each one-mile-square block of mud they are sampling.  This means if they were to sample an area the size of New York City, they would find around 782 new species, and if they were to sample an area the size of London, they would find about 1,572 new species.  These new species add up fast – you see, there are 300,000,000 square kilometers (115,830,647 square miles – almost 30 Europes or 431 Texases) of mud deeper than 1000 m in the ocean. The end result of all this is a conclusion of 300,000,000 species living in the mud at the bottom of the deep ocean.  This is not counting swimming things!  That’s a heck of a larger estimate than the 176 species estimate of centuries ago.

.It turns out that this calculation of Grassle and Maciolek was probably a bit of an overestimation.  They realized that much of the ocean is oligotrophic, or not very nutrient-rich and therefore not very productive.  This would mean that in many areas of the ocean, the rate of new species added per square kilometer is probably much less than what they found in their sampling area.   So, they ended up conservatively estimating the true number at more like 10,000,000 species in the mud. This is still a huge amount of diversity in the deep sea.

Grassle and Maciolek’s 10 million species hypothesis sparked quite the controversy, with biologists from many sub-disciplines quickly arguing for or against the high number.  Isopod biologists Poore and Wilson said they had seen even more diversity just among isopods in their samples than the average number of species per 100 samples that Grassle and Maciolek had used in their calculations.  This, they argued, must mean there are even more than 10 million species!  In 1971, though, Thorson argued that there were only 160,000 species in the oceans across all depths- so far less than 10 million could be in the deep sea.  In 1992, May argued that only 500,000 species would be possible in the deep sea.  Lambshead in 1993 reminded everyone that there are a boatload of nematode worms and other animals (collectively called meiofauna) that live in the mud that were too small to be sampled by the gear Grassle and Maciolek used.  This, Lambshead argued, could mean a total of 100,000,000 marine species.  Consensus just could not be reached.

Here’s the problem, though.  It is a hard question to answer.  Each person who has attempted to answer this question was doing the best with the data that they had at the time (except Pliny- that guy was just an idiot okay). However, species diversity and especially how many species you discover in each new deep-sea “block” can vary considerably at different depths, regions, and oceans. Grassle and Maciolek’s encoutering 3 new species per block was based on data from the North Atlantic. Does 3 new species “rule” also apply to other parts of the Atlantic or to the Pacific? So without massive amounts of data, it is likely we will be kept guessing for a few more years to come. So, I can’t tell you exactly how many species are in the deep sea, but I can tell you that we currently have 409,543 named species in the ocean (World Register of Marine Species, accessed 03/18/2019).  The best part is that we are getting better and better at discovering new species, and hopefully in years to come we will be much better equipped to answer this question realistically.

Cover photo credit to Monterey Bay Aquarium Research Institute (MBARI).

The post How many species are in the deep sea? first appeared on Deep Sea News.

Assigning a vernacular or ‘common name’ to a new species was usually never part of a taxonomic description, and we scientists were happy to use the Latinized lingo as an insider’s secret form of communication.  Definitely not as lame as two nerds speaking Klingon to each other, but as friend once said to me “Dude, that new Hydrolagus melanophasma is a totally kickin’ holocephalian!”, and I knew exactly what he meant. And indeed it was kickin’.  But consistent use of an understandable common name is more important than ever if we want to better integrate science, conservation, policy, and education.  So here’s my story…

Last year, two colleagues and I described a new species of catshark from the Galapagos Islands, and dubbed it Bythaelurus giddingsi after underwater cinematographer Al Giddings, who helped video tape live footage of it, and many other critters, during a deep-sea expedition to the islands in the 1990’s. In the original description of our new species of catshark, we never gave it a common name, and in a moment of synchronicity, a colleague was finishing the draft of Sharks of the World, the catalog of sharks and one-stop shop for both academic and non-technical shark aficionados, and we needed to give it a common name that it would be forever referred by.  But where the rules of scientific names are loose, the creation of common names is much more strict. The American Fisheries Society has a handbook of rules for assigning common names, and points out many examples of inappropriate ways common names can be applied to a species. For example, it discourages common names honoring people, so “Giddings’ Catshark’ was out (sorry, Al), so was ‘Galapagos Catshark’ because this was one of several catshark species from the Galapagos.  But clause #11 of the rules states: “Colorful, romantic, fanciful, metaphorical, and otherwise distinctive and original names are especially appropriate. Such terminology adds to the richness and breadth of the nomenclature and yields a harvest of satisfaction for the user”.  Bingo.  I had it.

Our new shark was dark, but with scattered light blotches.  It reminded me of the scene in The Life Aquatic with Steve Zissou where the elusive and deadly Jaguar Shark swam by Team Zissou’s submersible, un-illuminated, and you could see the dark body with the light spots as it swam by the observation windows. I asked my colleagues if we could name our not-so-deadly discovery the “Jaguar Catshark”.  After all, catsharks were already known for their “colorful, romantic, fanciful” names, like the Pyjama catshark, Lollipop Catshark, Mouse Catshark, and there were already a Tiger Catshark and a Leopard Catshark, so ours worked. With their OK, I passed along to my friend for his book, and when it will be published this summer, Sharks of the World will unveil the Jaguar Catshark to the world.

Original description:
http://www.mapress.com/zootaxa/2012/f/zt03221p059.pdf

Sharks of the World
http://www.wildnaturepress.com/our-titles/sharks-of-the-world-7

Other Press:
http://www.calacademy.org/newsroom/releases/2012/catshark.php

The post Not Quite the Shark that ate Esteban first appeared on Deep Sea News.

Check out my new article on Wired. For fun you may want to check out the comments.

We are currently in a biodiversity crisis. A quarter of all mammals face extinction, and 90 percent of the largest ocean fish are gone. Species are going extinct at rates equaled only five times in the history of life. But the biodiversity crisis we are currently encountering isn’t just a loss of species, it’s also a loss of knowledge regarding them.

via The Mass Extinction of Scientists Who Study Species | Wired Science | Wired.com.

The post The Mass Extinction of Scientists Who Study Species | Wired Science | Wired.com first appeared on Deep Sea News.

Diversity is a matter of area.  This is because there is a well-known relationship between species and area, called rather cleverly the species-area curve.  You increase the size of the area sampled; you increase the number of species. However, this relationship is not linear as the term “curve” would suggest, i.e. species increase consistently with increasing area.  Rather as area increases, the rate at which new species are encountered decreases, a power law function. Think of it this way…you go to the beach and you begin counting species in a tide pool.  Everything is new to you so your tally quickly increases.  At tide pool 2 you find a few new species but some you have already seen.  10 tide pools in and you pretty much seen everything except an occasional rare species. You can see it might be useful to have set of descriptors that describe diversity over spatial scales.

Whittaker (1972) suggested that diversity had alpha, beta, and gamma components.
•    Alpha diversity-the diversity in a local area with uniform habitat type.
•    Gamma diversity-the diversity of a region, with region defined as a large area without major barriers to dispersal.
•    Beta diversity-is the change in species as you move from one habitat to another. If habitats contain generalists, species well equipped to survive anywhere, then beta diversity will low.  If habitats possess specialists, species geared for a particular set of environmental parameters, then beta diversity is high. This is also referred to as species turnover.

Thus regional, or gamma, diversity is both the number of species in a habitat and how many species the habitats share in common, i.e. Gamma=alpha diversity*beta diversity

Today’s example includes donuts.  I am writing this on Sunday morning before breakfast so you will have to bear with me.  My local donut shop, let’s call them Jimmy’s Donuts Extravaganza, serves 12 kinds of donuts…mmmm donuts.  So the alpha diversity at Jimmy’s is 12.

Now just last week, a new earth friendly, all organic vegan, donut shop opened nearby, Earthchild’s Goodearth Donuts.  They have 6 donut types.  Now there is no way that either of these places have the same types of donuts.  For starters, Jimmy doesn’t even no what vegan means or that alfalfa sprouts are cattle feed.  So there is no overlap in donuts.  If we define beta diversity on scale of 0-1, where 1 is complete overlap in donut types, then beta diversity between Jimmy’s and Earthchild’s is 0. So gamma diversity is 18.

Now a local convenient store, Kwik-E-Mart also carries donuts.  God help anybody who eats them.  Of the 12 they carry, 6 overlap with Jimmy’s.  Beta diversity between Kwik-E-Mart and Jimmy’s is 0.5 and as expected 0 with Earthchild’s. So now gamma diversity is 24 because all 12 of Kwik-E-Mart’s donuts are not new to my area.

Another new store, Big Ol’ Donuts, opens and it really just more of the same except for one new tasty donut that contains coconut sprinkles.  Although alpha-diversity of Big Ol’ Donut is high 19, only one donut is different, and thus donut gamma diversity of my area only increases to 25.

The post Biodiversity Pt. 2: Mmmmm…donuts first appeared on Deep Sea News.

KZ is now among the scientifically published. Occurring this week in the Proceedings of the Biological Society of Washington is “A new species of Alvinocaris (Crustacea: Decapoda: Caridea: Alvinocarididae) from hydrothermal vents at the Lau Basin, southwest Pacific, and a key to the species of Alvinocarididae“, Kevin’s very first published paper!  I might add here that I am rather impressed that his first paper also happens to be description of a new species.  This new species is not just some uncharismatic, minute, amorphous organisms live in the muck of the seafloor…like the ones I study.  No ladies and gentlemen this is a real contender for charismatic megafauna.  Zelnio and Hourez describe an new species of Alvinocaris, an abundant an important shrimp globally at hydrothermal vents.  A. komaii is bigger and more probably more bad ass than all the other Alvinocarids.  Of course bad ass is hard to quantify, you just know it when you see it, and there are much better defining features, notches and spinules, but KZ can tell you all about that.  But Zelnio and Hourdez don’t stop there with a description of new species.  Oh no boys and girls, you also get a a pratcial guide to to all the species in the family with localities.  But now for a limited time, they are also offering a molecular phylogeny of the group.

Seriously though, your first published scientific article is a thing of pride and a very special time.  Raise your glasses…and drop a line here congratulating Kevin.

The post Kevin Zelnio…New and Improved…Now With 30% More Shrimp! first appeared on Deep Sea News.