sam with pedder trout

Glimpses of a limnologist: Sam Lake

Interviewed by Ebb in December 2014


Welcome to the Moray’s Lair, Professor Sam Lake. How are you?

I’m fine–still fairly intact and supposed to be retired. Besides doing some travelling, fishing and grandfatherly duties, I’ve maintained an active research scope mainly concentrating on the restoration ecology of stream ecosystems, and on the effects that hydrological extreme events (floods, droughts, catchment bushfires) have on these ecosystems.

Sam, I first heard of you when I transitioned to the freshwater world, and my first boss with freshwater leanings, the aquatic botanist, Dr Jane Roberts, mentioned you. She spoke very highly of this Sam Lake guy from Monash University and said that I should read his limnological writings along with those of Keith Walker. At the same time she dangled the carrot that you had started you’re career out studying fishes, including galaxiids in Tasmania. I seemed to recall something about you netting or setting traps from a rowboat, however, this could be the fog settling into my mind. How much of this is true, were you a pretty serious fisho in your day? Was there a rowboat?

I grew up in a rowboat. Watching my grandfather row and it was mesmerizing. Borderline Torvill and Dean stuff.

For my Honours from ANU, I investigated the heavy metal pollution of the Molonglo River near Canberra and subsequently won a British Commonwealth Scholarship to the University of Southampton.

I did my Ph.D. on the neurosecretory system of a fairy shrimp for which I received the Thomas Henry Huxley Prize of the Royal Zoological Society of London. In the Zoology Department of the University of Tasmania, initially I did research on the neurosecretory systems of some crabs and shrimps and lectured in ecology, freshwater ecology and cell ultrastructure—a quite bizarre mixture. Then steadily with enthusiastic, and oft unruly, students, colleagues and very capable technicians (Ron Mawbey, Tas Sward), I moved on to research on freshwater crustacean ecology, the biology of the Bastard Trumpeter, on freshwater fish diversity, and on heavy metal pollution in the South Esk River and in streams of western Tasmania. While I came across galaxiids in places, I definitely did not start my research career studying fish per se. Also at this time, I became very involved in the conservation campaigns such as trying to save the original Lake Pedder and to resist the establishment of a woodchip industry in Tasmania.

Colleague of Sam Lake's fishing in Penstock Lagoon Reduced

One of Sam’s colleagues angling in Penstock Lagoon

Thus, I would say that in my day and throughout my travails, I’ve definitely not been a serious “fisho”. Sure, I’ve encountered many fish in my research, but I tend to see them as a component, sometimes a major one, of freshwater ecosystems. Indeed, one of the many things missing in Australian freshwater ecological research is an understanding of where fish fit into the structure of freshwater ecosystems. How do they influence the trophic structure and productivity of such systems, how are they themselves influenced by the structure and productivity of freshwater ecosystems?

On the use of rowboats, I used to row a dinghy during the trumpeter research while the boat master, Tas Sward, set or hauled in nets off Bruny Island. In investigating the changes in the littoral fauna of Lake Pedder, before and after it was flooded, I along with a range of colleagues—Ron Mawbey, Richard Norris, Dave Coleman, Alastair Richardson, Rob Sloane et al., —used a variety of boats, including one owned by Ron’s dad, to sample the littoral fauna for 15 years. Sampling went on in spite of the weather, hot calm fly-rich days and days of storms, even when surrounded by waterspouts.

Please tell us a little more of what was going on in your mind, back then, with regard to fishes and limnology? I’m especially interested in your thinking broadly about freshwater systems and whether you were focussed on local systems and particular taxa?

At ANU, Alan Weatherley, a very notable fish biologist, taught a course in freshwater ecology. This covered the basic physico-chemical attributes of both standing and running waters along with the biology of the major fauna. He certainly encouraged an ecosystem approach to the study of freshwater systems. So, for example, while he studied the effects of heavy metal pollution on fish in the Molonglo system, he encouraged me to investigate the invertebrates, and these two components combined with the water chemistry from John Beever, formed a chapter in the book “ Australian Inland Waters and their Fauna” edited by Alan. So, I would say that while the Molonglo was a local stream; the approach was system directed.

Alan along with colleagues such as Ian Bayly and Bill Williams promoted the ecosystem approach to freshwater systems. This influence was particularly marked in the 60 and 70’s when limnology in Australia was mainly concentrated on lentic (standing water) systems. Ecological investigations of flowing waters did not really emerge until the 80’s, and initially it was concentrated on the dynamics of particular populations, species and assemblages rather the dynamics of flowing water ecosystems. This was no doubt due to the ignorance of the biota in waterways, but also possibly to the difficulty of trying to understand such dynamic and non-equilibrial systems. Indeed even now, in Australia we know much more about how to degrade streams and their catchments than we know about how they function as ecosystems.

One of the countries more experienced fish ecologists, Wayne Fulton, must have been cutting his teeth in the trade around that time, how did you two work together?

Wayne Fulton was a student in the mid 70’s with a scholarship from the Inland Fisheries Commission and he subsequently did a Master’s degree (partly supervised by me) on the biology and distribution of freshwater fish in Tasmania. From his thesis he produced a book for the Fauna of Tasmania Series published by the University.

Wayne was a collaborator on a study of fish distribution in a small coastal stream, Parsons Bay Creek, near Nubeena; from where Wayne hailed. The study was published in Papers and Proceedings of the Royal Society of Tasmania and data from that study and a few others was to discern spatial patterns of diversity in small streams. Also when doing his M.SC., Wayne discovered that the genus Paragalaxias was represented not by one species but four. I remember discussions about this notable discovery.

Wayne went on to become the Commissioner of the Inland Fisheries Commission followed by being a Program Leader in Fisheries Victoria. The last time I met him was at a workshop at Snobs Creek on fish restoration. I gather that he is now a Consultant based in Bendigo.

It seemed like you had a few prominent limnologists around you in Tasmania, including Richard Norris. In the absence of the internet and presumably in a time where publication turn around time was relatively slow, did you have a sense of other researchers beyond your university and elsewhere in Australia in those days? I mean I’m guessing coming together for an Australian Society for Limnology Meeting must have been a major chance for knowledge exchange?

Sure, even before going to Tasmania I knew quite a few limnologists, either through Alan Weatherley or through going to ASL meetings. Such notables include Aubrey Nicholls, John Lake, Ian Bayly, Bill Williams, Ron Strahan, Hamar Midgeley and many more. ASL meetings were very friendly and warm-hearted in those days. And yes, at the conferences there were many exchanges of knowledge, information, opinions and other more secretive deals and activities along with the odd disagreement. In all, they were very enjoyable meetings.

In Tasmania I supervised quite a few honours students working on freshwater problems, and some worked on fish-related topics (e.g. Mick Cassidy, Rob Sloane, Gary Bennison). However, I only supervised four Ph.D. students with the final one being the late Richard Norris. He did Honours with Alan Weatherley and sometime over Christmas in 1973 (I think) he phoned me and said he wanted to talk with me. He very promptly turned up and over a meal and some wine in the dark watching the shimmering wonders of the Aurora Australis, he decided to do his Ph.D with me. He worked on the ecological effects of cadmium-zinc pollution of the South Esk River and produced an excellent thesis and then went onto remarkable success.

I still have the hardcopy sent from a librarian of one of your papers, describing the electro-fishing of Brown trout and a number of native fishes in a stream in the Hobart area. Amongst the catch was the Tupong (Congoli) a species that was featured recently by Chris Bice here at the Lair. Can you give us a sense of what you thought of that species at the time – and relate it to what we now know of its ecology thanks to the recent work of Crook et al. and Zampatti and colleagues?

The paper was the one mentioned earlier in relation to Wayne Fulton. And yes, Tupong were found at sites near the estuary. I knew that they were tolerant of a wide range of salinity, were related to Antarctic Icefish, and that little was known of their biology. Later on Mick Hortle and Dave Crook worked out aspects of their biology and their catadromous life cycle.

I think pretty much all of our audience will realise that you are a heavyweight of the limnology scene, but here at the Lair we crave information in the ichthyosphere. So I’m going to try and keep you hemmed in. Apparently, you visited one of our spiritual homes, the Narrandera Fisheries Centre in the 1960’s. Are you able to give us a sense of what that was like back when?

I only visited Narranderra Fisheries Centre once and that was to attend the 2nd ASL conference in 1963. I gave a paper on my pollution work and was very embarrassed by the revelation that I’d misidentified one of the key trichopteran families. It was a cold and rainy conference and I remember a fine array of gabardine overcoats being worn as delegates watched Golden perch being caught out of one of the breeding ponds, and the clouds of cigarette smoke at tea breaks. It was an enjoyable and inspiring conference at a venue with a big influence on freshwater fish ecology and aquaculture.

Did you have much to do with the other famous Lake, Dr John Lake?

Perhaps not all that much, I’m afraid. I did meet John quite a few times, especially when he visited Canberra to see and work with Alan Weatherley, and also at ASL conferences (Narranderra, Canberra, Lismore). I had quite a few conversations with him, especially in the early 60’s, and I always found him to be very helpful and inspiring. He was a gentle and generous person with a wide and profound knowledge of freshwater fish biology. He lost his house and precious belongings when Cyclone Tracey hit Darwin in 1974.

sam starting research at Lake pedder 1972

Sam in 1972 starting his research in Lake Pedder

You have supervised a number of the who’s-who of Australian freshwater fish ecology scene, including Paul Humphries, Gerry Closs, Alison King and Nick Bond. Care to give us some insights into how some of these researchers have shaped you’re thinking about the roles fish play in ecosystems, or perhaps how you have influenced them?

I suppose that during the 80’s I got interested in the fauna of temporary freshwater systems. Work by the MMBW drew my attention to the fish Galaxiella pusilla. This fishwas regarded as being unusual in that it lived in temporary wetlands east of Melbourne. Thus, Paul Humphries studied the biology of the fish for his Honours. It appeared that while the fish readily tolerated low quality water and low water levels, it was uncertain if it was truly desiccation-resistant. His thesis was unfairly marked. However, this setback did not extinguish his interest in fish as he did an M. Sc. in Tasmania on Galaxias truttaceus and a Ph.D in Western Australia on estuarine fish ecology.

After a stint in Tasmania, Paul was recruited by the CRC for Freshwater Ecology to head the environmental flow program. Originally, the flows were to come from Eildon, but this proved to be totally unfeasible, and so the focus was shifted to releases from Eppalock Dam on the Campaspe River, with the Broken River as the partly regulated control. For various reasons related to dam operations, the environmental flows never eventuated. However, Paul managed to gather a large amount of information on the biology of fish in these two systems, notably knowledge on larval fish ecology. Subsequently Paul joined the Charles Sturt University at Albury. We regularly meet and plan things.

It was by way of Paul that I met Alison King who consequently did a great Ph.D. on larval fish ecology and breeding patterns of fish in relation to flow and floodplain access.

Gerry Closs (“Clossy’) was an ardent “fisho” who came across from La Trobe University to Monash to do a Ph.D. Andrew Boulton (of all-weather thong fame) had worked in the intermittent upper Lerderderg River and, with various forms of persuasion, had compiled an amazing understanding of how the invertebrate assemblages changed with flow. And so a rather crestfallen “Clossy” was set to describe the food web dynamics (invertebrates and fish) in the river as the flows rose and fell. It was a remarkable and detailed piece of work, subsequently published in Ecological Monographs and highly cited. Coincidentally with this work, he managed to show that cease-to-flow episodes and drought removed trout populations and allowed galaxiids to return. Clossy subsequently went to the University of Otago—a very productive centre of freshwater ecology.

Nick Bond came across to Monash from the University of Melbourne as a post-doc. At that time I was venturing into the restoration ecology of streams. Nick has some elements of wanting to become a “fisho” and thus worked on the possible restoration of fish in the Granite Creeks. He elucidated the habitat structures favoured by the species and we managed to get a positive response to habitat restoration before the Millennial Drought struck. Subsequently, he compiled data on the survival and recovery of fish populations in the creeks and from this along with the skills of George Perry drew up a robust model of how the fish populations coped with the fluctuations of flow and water availability. Nowadays, he works at Griffith University on a variety of projects.

I’m not sure whether the interactions with my colleagues have actually shaped my ideas about how fish influence ecosystems. In the intermittent systems we’ve worked on, the fish comprise the most sensitive component to changes in flow, especially when droughts occur. Whether they have a strong influence on food web structure and productivity is uncertain, but I sense that in these intermittent systems their effects are minor.

The environment flow (or lack of) work did reveal that heavy river regulation, such as in the Campaspe, can have powerful effects on fish biology and thus on community structure. The importance of both floods and low flows for reproduction and population growth was borne out by the comparison between heavy and low levels of flow regulation in the work by Paul Humphries and Alison King.

So, overall, in these intermittent systems fish may be a spasmodic player and the major active elements in such ecosystem range from the microbial to the invertebrates.

Sam, now for a biggie. Where do you see Australian freshwater fish ecologists making a difference in say the next 20 years?

This is a hard one to answer as it requires me knowing what fish ecologists want to do and what they are skilled in doing. The big gap in my opinion lies in the ecosystems dependency of fish. What do they do to influence both the structure and function of aquatic ecosystems in Australia and what needs to be supplied by ecosystems to engender and maintain viable fish populations.

While there is knowledge of basic fish biology, important areas such as linkages between primary and secondary productivity (including fish), the influence of invaders on productivity and food web structure, the roles of extreme events (floods and droughts) on trophic structure, ecosystem production and fish populations, and the influence of catchment systems (including riparian zones) on fish assemblages need to be addressed. There are many more areas, but the key point is that the understanding of the role of fish in freshwater ecosystem structure and dynamics is critical, but it remains poorly understood and un-investigated in Australia.

While I ‘ve stressed research in running waters, it is somewhat surprising to see that fish ecology, especially in relation to production and trophic ecology, in lakes and impoundments appears to be also neglected. Even if such research deals with introduced fish (such as the work by R. Tilzey on trout in Lake Eucumbene) knowledge of production dynamics could greatly help fishery management.

A lot of my suggested areas for research require attention in order to guide the restoration of flowing and standing waters in Australia. This particularly applies to the restoration of fish populations, where in many cases fish have been the sole concern without consideration of the structure and production characteristics of the ecosystem. Fish can be very tough and versatile, but being in most cases apex predators, their success is critically linked to ecosystem trophic structure and levels of production.

Thanks for your insights and recollections Sam. I’m sure our following appreciate you taking the time to put your tales on the record. And may others have the same joy of randomly meeting you at airports from time to time.