Revisiting Menge 1976

In 1976, Bruce Menge published a paper in Ecological Monographs reporting the results of his experimental and observation studies on the factors structuring the rocky intertidal community along the New England coast in northeastern United States. This paper, which came six years after the completion of his PhD,  marked the beginning of Menge’s interest on community-level patterns and processes, an interest that has remained till today. Forty years after the paper was published, I asked Bruce Menge about how he got interested in this area of research, memories of field work, and what we have learnt since about the factors structuring rocky intertidal communities.

Citation: Menge, B. A. (1976). Organization of the New England rocky intertidal community: role of predation, competition, and environmental heterogeneity. Ecological Monographs, 46(4), 355-393.

Date of interview: 12th August 2016 (via Skype)

 

Hari Sridhar: I would like to start by asking you about your motivation to do the work presented in this paper. I found out that this paper came out six years after you finished your PhD, and that this is probably only your second paper looking at community-level patterns. Your work before this was focused on single species or pairs of species. Could you tell us a little about how you got interested in this community-level question?

Bruce Menge: When I was doing my PhD, a fellow graduate student was Paul Dayton, who you have probably heard of. For his thesis, Paul did a study on the west coast up in Washington, in which he did the same thing at a bunch of different sites. Dayton’s study, when he did it and when he published it, really impressed me a lot. When I went to New England, I knew I wanted to do more community-level stuff. I wanted to expand to a larger scale. So, I started going out on the rocks there and looking around, and I saw a system that, first of all, hadn’t really been studied in terms of community ecology before. And secondly, there were some pretty striking patterns there. So, I decided to embark on a study that was like what Paul Dayton did, in multiple sites, some in more sheltered areas and some in more exposed areas, investigating predation and competition, which, I thought, were probably the main interactions in this community. I set up experiments that would test that, and the 1976 paper was a result of that work.

 

HS: Stepping back a bit, could you tell us a how you got interested in the marine system? Did an interest in marine life come first or an interest in ecology?

BM: I got interested in ecology first, when I was an undergraduate at the University of Minnesota. We have no oceans there! But I knew that I didn’t really want to work in terrestrial environments or lakes or whatever. Growing up in Minnesota, there were a lot of mosquitoes, and I knew I just wouldn’t enjoy a field site that had that problem. Summers were ultra-hot, winters were ultra-cold. As I kid, I had visited Florida with my family and saw Manta rays swimming in the ocean and thought it was really exciting. So, I decided to do marine research. When I was graduating, I applied to several schools that had marine labs and chose to go to the University of Washington, which has, probably, the best marine lab in the world. But I didn’t really know it at the time. This is the 1960s. I was pretty naïve about how to go about getting into graduate school. I didn’t really know what graduate school meant. So, it was serendipitous that I decided to go to Washington and it turned out that was probably the best place I could have gone to. When I got there, Bob Paine assigned me to him as a major professor. I told him I wanted to do ecology, I wanted to work in marine systems and so he assigned me to him as my advisor. It took a while to figure out what I was going to do, but he was very encouraging. He was studying a large sea star that occurred on the rocks along the whole west coast, and inspired by that, I decided to study a smaller sea star to see how it compared to the larger sea star.

 

HS: You say this work was done between 1972 and 1975 and you were sampling almost every month of the year. From reading the paper, it looks like you did an incredible amount of field work. Could you give us a sense of field work – did you work mostly on your own, what was a typical day in field like?

BM: My wife is Jane Lubchenco and she had accompanied me to Boston and eventually got into graduate school at Harvard. For the first year, she was basically starting her PhD research even before she was actually in graduate school. She and I worked together. The way we decided to divide things up was that she would look at plant-herbivore interactions and I would look at predator-prey. In addition, in my first year at University of Massachusetts, an undergraduate student came to me and volunteered to work for me. He wanted to come out and work on the rocks with us. So, basically, it was a team of three – this guy, Jane and me. We worked together and set everything up and we helped each other whenever needed.

 

HS: What was the undergraduate student’s name?

BM: His name was Steven Garrity.

 

HS: I’m just looking at the acknowledgements section. In addition to Steven you mention a number of other people who also helped you in field.  Were they also undergrad students from your university?

BM: The first two are Jane’s sisters. They would come out occasionally in the summer and we would put them to work! And there were also other undergraduates who helped in the summer. Eventually I got access to work study students. So, while Steve Garrity was my main assistant, there were others who helped mostly in the summer. Others were individuals who read the MS and gave me comments on it. Vance and Woodin were both fellow graduate students at UW. Jackson, Sutherland, Sousa and Schoener were colleagues at other universities, Kohn was a member of my PhD committee at UW, Rex and Hatch were colleagues at UMass Boston, and Riser was the director of Northeastern University’s Marine Lab at Nahant, where some of the work was done.

 

HS: Do you continue to work in the sites you sampled during this study?

BM: Not personally. But a couple of my former students, Matt Bracken and Cascade Sorte, had positions in Boston. Matt was at Northeastern University and Cascade was a post-doc at UMass Boston. I visited them once and I was able to go and look at some of these sites at Nahant and in Boston Harbor.  The differences from the 1970’s to the 2010’s were stunning. It was the first time I’d been here since 1979-80. I have been working in other areas, for example the US west coast and New Zealand and other places. But Matt and Cascade picked up on some of this work and, actually, Cascade, some of her students, Jane and I have a paper in Global Change Biology which takes some of our data from the 1970s and puts it together with their data from the 2000s, and looks at whether or not, and how, this particular system has changed. It appears to have changed a lot since the 70s. Matt, Jane, a former student of ours (Heather Leslie) that was at Brown University at the time, and I also published another paper in Ecosphere that looked at how algal abundance had changed in an experiment begun in 1974. It was a productive trip! But in response to your question, except for the brief trip, I think in 2009, I haven’t been back there.

 

HS: You say in your paper that none of the areas you sampled experienced noticeable human damage. Is that still the case today?

BM: One of the things that has happened in the 40 or so years since the 1970s is that mussel abundance has declined and we think that it is mostly due to climate change although we can’t say for sure that collecting by humans hasn’t had an impact as well. There has been an increase in collection of mussels along the coast. But I think mussel decline was the primary change and it was most likely due to warming, which good evidence indicates has happened during the past decades. Another factor is that two of our sites are on islands which are inaccessible to people or at least, rarely visited. The other was on the property of the Northeastern University marine lab where the amount of human traffic allowed is minimal. It’s also difficult to walk on the island, especially when there is a lot of algal cover. Seaweed cover makes it very slippery, so you don’t really see many people out on these rocks. And a relatively recent study has shown that the southern limit of this mussel has retreated northward by a lot over the last few decades.

 

HS: What about the two other main species in this study – the barnacle and the snail – have their populations undergone significant changes?

BM: The predatory snail has declined pretty sharply as well. It makes sense because the mussels are one of its main foods. Barnacles, in contrast, have actually increased in abundance since the 70s. Not a lot but some. Seaweeds have also declined in abundance, at least in some places. And that is probably another effect of climate change. So yes, there are big changes happening along the New England coast.

 

HS: Do you remember how long it took you to write this paper, and where and when you did most of the writing?

BM: I did it both at my office in the university and at home. This was before computers, so I wrote it up by hand and then typed up the MS for submission. I did all the analyses on a small hand calculator, a Hewlett Packard 67, which I actually still have. In terms of the analysis, it probably took a couple of months.

 

HS: Did the paper have a relatively smooth ride through peer-review? Was Ecological Monographs the first place you submitted it to?

BM: Yes, it wasn’t too bad, as I recall. I remember I got some pretty good reviews, I modified it accordingly, but it went through fairly quickly. And EM was the first place to which I submitted the paper.

 

HS: You said you didn’t have computers at that time. How did you draw the figures for this paper?

BM: We used drafting tables and drafting equipment. I had a Leroy Lettering Set made by Keuffel and Esser, which had templates for letters, numbers, etc. You used a stylus that followed the grooved letters on the templates, and wrote the letter on white drafting paper. You just had to space everything by eye, and judge letter sizes the same way. Mistakes could be covered with something called “white-out.” Because you wanted to avoid having a lot of do-overs, I’d make all figures by hand beforehand on graph paper.

I doubt that Leroy Lettering sets are still made; when I looked on the web, they are referred to as vintage, and available on sites like ebay. I looked up K&E and it looks like they went out of business many years ago.

 

HS: Do you remember if this paper received a lot of attention, in academia and the popular press, when it was published?

BM: There was certainly no popular press interest in it. There was very little of that sort of stuff in those days. But I got a tremendous number of reprint requests, which, in those days, was the way you found out if people were interested in your work. You would get a postcard requesting a copy of the paper. Typically, in those days, you would get a few hundred reprints from the journal. I probably mailed out well over 500, because I remember I had to ask for them to be recopied. I ran out of the original reprints.

 

HS: This paper has been cited over 800 times. Do you know what it mostly gets cited for?

BM: I think it gets cited for several things. One is for the variation in predation and competition along an environmental stress gradient. The other is facilitation of mussels by barnacles, disturbance of barnacle recruitment by algal motion on the rocks, and blocking of settlement of barnacles and mussels by the dense canopy of seaweeds. There were a number of different things in there, and so people cited it for multiple reasons.

 

HS: What kind of impact did this paper have on your career and the future course of your research?

BM: It had a very strong influence on the course of my research. I have pursued similar sorts of things in other areas, like here on the west coast, in New Zealand etc. My students have worked in other places like Chile and South Africa and Ecuador. This was also sort of a foundation for continued expansion to consider not only effects of environmental stress but also things like productivity, how that affects these systems, how these things vary on very large scales. That’s what I have been looking at recently, the influence of oceanic variability on rocky shore ecosystems. So, I think this paper had a pretty major effect on my career. It was on the basis of this paper, and couple of others from the New England research, that I got this position at Oregon State University in the late 1970s. We had always wanted to be on the west coast of the United States, so this was sort of part of a launch pad to getting that going.

 

HS: Today, 40 years later, would you say that the paper’s main conclusions still hold true, more-or-less?

BM: Yes. In fact, there is a recent study, in 2010 or thereabouts, done by Elizabeth Bryson, a graduate student at Northeastern university. She repeated a number the kinds of experiments that I did, and found similar patterns – strong predation in wave-sheltered areas and weak predation in wave-exposed areas. That was really interesting.

 

HS: If you were to redo these experiments today, would you do anything differently, given the advances in technology, theory and analytical techniques?

BM: I would do more monitoring of the environment. Put out temperature loggers and measure temperature at different heights and different wave exposures. I would measure things like phytoplankton availability for the filter-feeding invertebrates. I would measure currents along the shore if I had access to the right equipment. Basically, I would get a better idea of what the oceanic conditions were, as well as sort out the subjective differences that I knew occurred among the sites, including measuring wave action. I would put out wave force sensors as well. The biology and experiments would pretty much be the same, but the physical side of things would be better documented.

 

HS: In the last sentence of the paper you say, “Exactly how widely this generalization [i.e. that predation and biological disturbance are most often the biological agents regulating community organization] applies in nature awaits further research at the community level.”

To what extent has this happened, and do you think the conclusions of your study have been validated by findings from other studies in other systems?

BM: Yes, I think so. There have been many studies in other systems that found similar sorts of results – major effects of wave action on the rate at which predators or herbivores feed, and strong impacts of environmental stress, especially at higher shore levels. And even people working in aquatic and terrestrial environments have found some similarities to these kinds of results in their systems. I think it has proven to be a fairly general sort of idea.

 

HS: You did your PhD with Bob Paine, and it looks like you did your first postdoc with Joseph Connell. Would you say that Paine and Connell had a strong influence on the way your research career panned out?

BM: Absolutely. In those days, back in the 50s and 60s, the idea of doing experiments in the field was not common. Joe Connell did his experiments in the early 50s and he was really a pioneer. Absolutely no one had done those kinds of studies. Paine’s experiments in the 60s were also incredibly important. At the time, most of the focus was on competition and how that allowed species to coexist, but it was done non-experimentally. You would make observations and then make inferences about how important competition might be. What both Connell and Paine did was that they demonstrated, first of all, that competition is, actually, only important under certain circumstances, and that predation is a really powerful effect at least on the rocky shore systems. By the 1980s, it was pretty clear to most of the ecological community that competition is way less important than people had thought up to that time, and predation and herbivory were powerful forces in structuring communities. I think Paine and Connell, really, set the stage for much of what’s happened in ecology since.

 

HS: Have you ever read this paper after it was published?

BM: I think I did once. I’ve certainly gone back and looked at certain parts of it, just to refresh my memory on some aspects. But it’s been a few years since I’ve read it.

 

HS: You said you read it once. Do you remember what that was for?

BM: I’m not totally sure but I think I had a couple of motivations. I just wanted to refresh my memory on what I had done. It was a pretty lengthy paper and we did a lot of different things. I also wanted to see what my writing was like back in those days.

 

HS: If you compare the papers you write today, to this paper, do you notice any striking differences in the way you write?

BM: I wouldn’t say a lot of differences but I think I’m a better writer now than I was then. It certainly comes more easily to me.

 

HS: Would you count this paper as one of your favourites, among all the papers you have written?

BM: Yes, certainly. If I have 10 favourite papers then this is definitely among them.

 

HS: What about this paper do you like?

BM: The scientific discoveries were very exciting at the time and they still have resonance now. I covered a bunch of issues in that study which were and still are important. The fact that it is still cited fairly often tells me that the ecological community also considers it to be an important paper for helping to set the parameters of modern community ecology. I like the comprehensiveness of it.

 

HS: What would you say to a student who is about to read the paper today? What should he or she take away from this paper written 40 years ago?

BM: I probably wouldn’t tell them anything. I’d suggest that they might want to read it, and, if they want to, we can chat about it. But I try not to give graduate students specific suggestions for how they should think. I want them to think on their own and learn things in their own particular way. So, I most likely wouldn’t tell them anything!