Cocktail Week: Dark n’ Stormy Effects on Kelps

It is cocktail week over at Deep Sea News. And it has been glorious, with marine biology themed cocktails galore. As a cocktilian myself, I felt that I had to kick in, well, a real classic. I classic that, I daresay, may lay at the root of kelp forest ecology itself. And yet may be under threat.

“Wait, what?” I hear you saying. Let me explain.

Kelps are incredible. I mean, this is a clade of algae with members who can grow a foot per day, that form giant forests that rival the redwoods in beauty, that embrace diversity looking like everything from a mini-palm-tree to a majestic pair of antlers 60 feet high, to a lasagna noodle.

The awesomeness of kelps knows no bounds.

What is truly incredible about kelps is the way they feed the whole frackin’ shorline. Not only do they get nibbled on by all manner of snail, amphipod, urchin, and fish, but they also shed off prodigious amounts of sea-snot (a highly technical term) that can nourish rich productive bacterial communities. But they don’t stop there. This delicious mucilage and bits of kelp ripped off and churned up in the surf into tiny little bits can get recirculated by all manner of filter feeders hanging around on the sea floor. So, they feed grazers and filter feeders and bacteria, all at once, without breaking a… well, ok, maybe you can consider their mucous ‘kelp-sweat’, but, you get what I’m saying.

Would that only be the way they feed the world around them, it would have been enough. But kelps don’t stop there.

Rather, the lose a ton of their prodigious productivity all the time. They’re constantly sloughing off ends of blades, whole fronds, and in storms often whole individuals come loose and fly out into the ocean only to settle down and get eaten by all manner of scavengers. Heck, kelps are so awesome, that they turn many hungry grazer into passive little detritivores who sit and wait for kelpy manna to rain down on them. And not just in the ocean, but up on beaches, too! They feed the ocean, *and* the land.

Wooo!  Kelp in flow!  Food for all! From http://www.clf.org/blog/ocean-conservation/treasure-on-cashes-ledge-an-ocean-refuge-in-need-of-protection/

Wooo! Kelp in flow! Food for all! From http://www.clf.org/blog/ocean-conservation/treasure-on-cashes-ledge-an-ocean-refuge-in-need-of-protection/

(FYI, for a lot of the references on this, see excellent work by folk like Kira Krumhansl, Dan Reed and the good folk at the SBC LTER, Dave Duggins, and many more)

That storms are a major driver of kelp detritus getting shunted out in to the vasty deeps and sunny sands is a major paradigm in kelp forest research. We see correlations between wave heights and kelp loss in many systems, and the major kelp die-back of the year in many systems is often correlated with the biggest storm events of the year.

So the threat? A fascinating piece this week in Limnology & Oceanography by Bettignies et al. that details kelps in Australia eroding into detritus not because of storms, but rather potentially as a tradeoff for reproduction. As they reproduce, tissues become weaker and slough off. However, once sloughed, the smaller more svelte kelps are actually more resisitant to the high wave action that comes right afterwards. So, while a broad-brush look might make it look like kelp loss happens around the same time as big storms, a close look at timing, physiology, and kelp adaptations shows that the story is far more interesting.

Will this hold elsewhere? Time will tell. But in the meantime, let’s drink a glass to big intense storms and their kelp-removing powers. I speak, of course, of the Dark N’ Stormy.

Dark-and-Stormy-1-1017x1024

I do not know the shrouded origins of this fine beverage, nor how it made its way into marine science. All I know is that at any marine lab I have visited, you will find passionate devotees. Long day in the field? Lab equipment break down on you? Stuck debugging R code while everyone else is in the fun and sun? Time for a Dark n’ Stormy evening. And if you have a favorite ginger beer? Be ready for some arguments.

And so, the Dark n’ Stormy (as taught to me maaaany years ago at a field station)

Dark n’ Stormy
2 oz. Gosling’s Black Seal rum
1/2 a lime
Ginger beer (I go with Reed’s and typically use 1/2 of a 12 oz. bottle)

Fill tall glass with ice. Pour over rum, juice of lime, and fill with ginger beer. Huck in your lime husk, stir, and sip. Contemplate the role of disturbance versus reproductive timing in kelp removal across the globe.

Why Michaelis-Menten Rules in a (simple) Lotka-Volterra World

WARNING: This blog entry contains me awkwardly groping with math. It’s not pretty. It’s not done elegantly – indeed, for problems of even moderate complexity I fired up maxima (which is totally awesome!) rather than screw up the algebra on paper. And there are a few leaps that I make that I’m sure someone could write a proof for, but, well… While I fall somewhere in the middle of the theoretical – experimental axis of scientists, that doesn’t mean it’s something I do every day, so, expect some turbulence. I welcome comments and suggestions.

And, indeed, despite my lit searching, I’m not entirely convinced that someone hasn’t done this before, so, I may be re-inventing a very old wheel. But I thought it might be interesting to post these thoughts, if only for my own processing of recent research results.

I also admit, showing some (clumsy) mathematical thoughts publically makes me feel, well, like I’m not wearing any pants. Oh well. Onwards! With or without pants!

So, I was intrigued by Kyle’s comment on my entry about the AJB diversity function paper. He said that surely theory must lead us to conclude that, due to only a limited number of species being able to pack into a space, a plot may never achieve some theoretical maximum amount of productivity as predicted by some curve.

This led me to think more about diversity effects, and why are they saturating, anyway? Should they be? It’s not Kyle’s original question, but, it’s an interesting one and leads down similar theoretical pathways (I think).

So I decided to go back to basic competition theory – the Lotka-Volterra competition equations. Continue reading

A Brief Residency at Deep Sea News

Hey, all! For the rest of the month, I’m the Scientist in Residence over at The Deep Sea News! Muchas gracias to Rick, Miriam, Kevin, and the rest of the crew for bringing me on board. My first post is up where I discuss some of my work on How are extinctions and invasions shaping food webs?

Also, contrary to what Rick may have you believe, I’m at NCEAS, not NESCent. hehe.

More posts to come!

The Map of Science

Why does it take so long for awesome cutting-edge statistical to make their way over to ecology? There are a myriad of techniques out there that have been around for 20, 30, 40, or more years that could help so many ecologists from banging their head into a wall over and over and over and…well, you get the point. But, it takes quite a while for them to percolate over to us. This is not for lack of user-friendly tools, often. Rather it has to do with the connectivity of disiciplines.

For example, I was having a lovely conversation with Jim Grace the other day about using Structural Equation Modeling for predictive purposes, and we ended up chatting a little about history. SEM as it is done currently – using maximum likelihood approaches to fit a model to a covariance or correlation matrix – really dates to the late 1960s and early 1970s. Before then, scientists in a number of disciplines used a wide variety of approaches to examine path models (a là Sewall Wright’s Path Analysis), or perform Factor Analysis, or approach other multivariate models that often included latent variables. These techniques were fairly heterogeneous, even though they attempted to do roughly similar things.

It took Karl Jöreskog‘s wonderful papers outlining his LISREL technique and software using maximum likelihood to really bring the whole enterprise together into modern SEM.

And yet, despite the fact that this seminal work was published in the 70s, there are Ecological papers well into 90s that use piecewise regression models to fit path analyses. Why?

The answer can be summed up by this beautiful diagram detailing the connectivity of science in 2004 from the ever-interesting eigenfactor.org (and hat-tip to Jim for pointing it out to me).

Orange circles represent fields, with larger, darker circles indicating larger field size as measured by Eigenfactor score™. Blue arrows represent citation flow between fields. An arrow from field A to field B indicates citation traffic from A to B, with larger, darker arrows indicating higher citation volume. Image from eigenfactor.org.

Basically, these methods were developed for economics, and saw their first heavy use there and and sociology, political science, education, and psychology. In terms of connectivity, Ecology & Evolution sites on the other side of a doughnut hole of communication (with the occasional exception of psychology). Historically, the fields where the newest techniques are being developed are rarely examined by ecologists, and it is to our loss. Fortunately, I think this is a historical trend. With the rise of search engines, message-boards, and copious mailing lists, I do wonder if a connectivity graph from 2004-2010 would be much tighter.

Connectivity can only be a boon for science. With environmental issues beginning to impinge on every endeavor, it has become more important than ever to survey the breadth of what is out there.

So, hey, sign-up for alerts for a journal that you think will have no relevance to you. Who knows what might drop into your inbox.

Lawrence Slobodkin: Trophic Pioneer

I just learned that Lawrence Slobodkin passed away last week. Slobodkin was one of the authors of the infamous HSS paper in 1960 that has shaped how we think of the role of predators in ecosystems for decades. Indeed, it is one of the very origins of the modern concept of trophic cascades. More than that, though, this was a man with broad ranging interests in biology. I think the New York Times Obit has some interesting points about his contribution to our understanding of the world, and includes this quote from Slobodkin:

Sometimes I chose research problems for their presumed importance, but often I was attracted by their beauty. My research and that of most of my friends is not a story of triumph but rather of fascination by nature.

A good model for us all.

The LTERs Get Hip!

It seems that blogs, twitter, etc, are beginning to really leak into the consciousness of ecologists! In two weeks, I’m attending the LTER All Scientists Meeting (ASM). As I browsed through the working grounp lists, I came across the following: Blogs, Posts, and Tweets: Potential Uses of Web-Based and Social Networking Media for Communicating LTER Science and Conducting Citizen Science.

Tres cool.

The LTER network, for those unfamiliar, is perhaps the oldest network of Long Term Ecological Research projects, well, anywhere. It consists of a collection of sites, each representing a different ecosystem type – from kelp forests to the arctic tundra to even urban ecosystems (oddly in my hometown). The data from these sites is largely out there and publicly available, and the network funds some really top-notch projects from established researchers and up-and-coming postdocs.

Whoops, how did that link get in there!

Because it is a network of sites sharing data and tools, there is a ton of cyberinfrastrcuture. Given the types of folk that has recruited into the project, I’m not surprised that the network is hip to blogs, twitter, and the like. And I’m pretty psyched that we’re having a working group on how to harness their power. Should be neat.