The Future of Dreissenid Control in Open Waters. Daniel P. Molloy State University of New York at Albany

Transcription

1 The Future of Dreissenid Control in Open Waters Daniel P. Molloy State University of New York at Albany

2 Acknowledgement of Conference Travel Grant

3 THIS PRESENTATION Outlines a game-changing, bold new paradigm for dreissenid control One with enormous potential as an economical and environmentally feasible method for the drastic reductions of dreissenid populations throughout North American water bodies

4 As its patent inventor, I take great pride that we now have the selective, eco-friendly, biocontrol agent Zequanox for dreissenid control Do we really need something in addition? Yes, we do Why?

5 Why?...Because in almost all infested water bodies, lake-wide treatments with ANY of the currently-available control agents are technically and economically unfeasible Not really feasible to treat entire water bodies with ANY whether they be a biocontrol agent like Zequanox or a chemical molluscicide.

6 Yes, relatively small high-value areas in lakes (e.g., unionid restoration areas, beaches, marinas, etc.) will be successfully treated, but these treatments will have little effect on the continual spread of dreissenids from lake to lake won t significantly reduce the ecological perturbations in the lake as a whole We will still have an AIS problem as the mussels in other vast, non-treated areas of the lake continue to degrade it and spread to other lakes

7 To stop the spread and halt the ecological degradation from dreissenids, we need development of a lake-wide control method NOT AN EASY RESEARCH TASK We need some foolhardy researcher to attempt it Well here I am.. Daniel P. Molloy at your service..

8 MY MINDSET AS A RESEARCHER I m a scientist who is attracted to looking for solutions to pest problems that have been considered by many to be intractable and unsolvable.the equivalent of looking for a needle in a haystack

9 In this regard, my lab has had major commercial successes in R&D for the Biocontrol of black flies with the bacterium Bacillus thuringiensis israelensis (BTI) a leader in this international effort Biocontrol of dreissenids with the bacterium Pseudomonas fluorescens (Zequanox) patent inventor

10 So my lab is now working on another needle-in-ahaystack project, i.e., development of the first agent for the control of dreissenids throughout an entire lake. These mussels have been in Western Europe for a couple of hundred years and nobody has come up with as effective lake-wide control method. Thus, control of dreissenids in entire lakes will be a very daunting challenge. --- another classic NEEDLE IN A HAYSTACK project.

11 SO WHAT KIND OF DREISSENID CONTROL AGENT IS NEEDED FOR LAKE WIDE CONTROL WHAT TYPE OF NEEDLE SHOULD WE BE LOOKING FOR?

12 No organization has the money for lake-wide treatments and subsequent re-treatments of entire lakes Thus the control agent ideally must be applied only once in a small area and be: -- self-perpetuating & -- self-spreading Thus, it must be alive It must be a biocontrol agent..and above all. it must be extremely selective for infecting dreissenids.. and among all types of biocontrol candidates, parasites (not predators) are the most specific killing agents

13 Hmmmm another one of those haystack projects Been there. Done that..

14 There s a needle to be found in there.. a lake-wide control solution in there

15 But hmmmm what s the best approach to finding it.

16 Ooops got carried away Nope this won t work..

17 Hey, why not try the traditional approach: Simply search in native range of that pest species for the candidate parasite

18 But two decades of sampling in Europe has led me to believe that this traditional approach simply won t be good enough Must think more outside the shell

19 There always are outside the box outside the shell control solutions

20 For example, would you believe me if I said I was going to find a needle in that haystack in 20 min using some outsidethe-box solution? Hhmmmm not possible? This traditional approach simply won t be good enough

21 Yep, it s very possible!!!

22 So. What is my outside the shell control approach to finding a lake-wide biocontrol agent of dreissenids? Here s a few slides listing non-pest plant & animal species whose populations are being drastically reduced in North America by parasites

23 American chestnut trees Fungus: American chestnut blight

24 Elm trees Fungus: Dutch elm disease

25 Bat populations are declining Fungus: White nose syndrome

26 In all three examples of drastic host population decline These species were/are naïve hosts infected by novel lethal parasites Novel parasites are species or strains that the naïve host: -- has not co-evolved with -- has not developed an immunity to -- has often been geographically separated from for millions of years

27 .but none of these three naïve species examples were bivalves.... so you might be skeptical that bivalves could also be naïve hosts and suffer population crashes.. You might be thinking show me that this could happen with a bivalve and I ll start to believe that maybe a novel parasite could be used to cause drastic population declines in naïve North American dreissenids..ok, then here s one..

28 In the 1950s, a spore forming disease caused catastrophic losses in eastern oyster populations on the Atlantic coast of the United States. The industry has never totally recovered from collapse during the 1950s. Eastern oyster Crassostrea virginica

29 After the 1950s, gone were the days when eastern oyster populations were abundant and the industry thrived

30 Within a few years in the 1950s, 95% of the eastern oysters were lost in high salinity areas to this MSX disease...and that spore-forming disease is still ravaging eastern oyster populations in those areas still 50 years later S = Maturing spores P = Young plasmodia

31 Now scientists know why this disease caused catastrophic declines in eastern oyster Crassostrea virginica populations The parasite that caused this disease was actually a species that normally infects a related oyster, the Pacific oyster, Crassostrea gigas, in Asia. The eastern oyster was a naïve host and it was exposed to a novel parasite!!!

32 So here s the novel twist, the short cut to finding the dream parasites for lake-wide control of our favorite bivalves - dreissenids INTRODUCE A NOVEL PARASITIC SPECIES/STRAIN THAT OUR NORTH AMERICAN DREISSENIDS WILL BE NAÏVE TO

33 and do not follow the traditional approach of simply searching for candidate parasites in native range of that pest species (as I initially did in this project)

34 and do not follow the traditional approach of simply searching for candidate parasites in native range of that pest species (as I initially did in this project)

35 Instead use an outside-the-shell approach, by searching for candidate parasites in the native range of a geographically-distant closely-related dreissenid species

36 .and in that search what are the characteristics of an ideal novel parasite

37 So here is.. THE TOP-TEN CHARACTERISTICS OF AN SUCH AN IDEAL NOVEL PARASITE

38 IT CAN INFECT BOTH ZEBRA AND QUAGGA MUSSELS 10

39 IT IS AN OBLIGATE (NOT A FACULTATIVE) PARASITE 9

40 IT IS EASY TO MASS REAR 8

41 IT IS EASY TO INFECT THE MUSSELS UNDER A WIDE RANGE OF ENVIRONMENTAL CONDITIONS 7

42 IT HAS A CLOSE COUSIN ALREADY INFECTING DREISSENIDS IN NORTH AMERICA 6

43 SO WHAT S THE BIG BENEFIT OF HAVING A CLOSE COUSIN PARASITE IN NORTH AMERICAN DREISSENIDS? Answer: The efforts spent on this side of the Atlantic studying the close-cousin in our North American dreissenid populations (i.e., getting familiar with its biology and ecology) will save significant amounts of time and money when it comes to studying the related species in Eurasian dreissenids To digress from our TOP TEN COUNTDOWN, here s an example of such a parasite..

44 Lake Ohrid in Macedonia -- My favorite place to look for novel candidate parasites for controlling our naïve North American zebra and quagga mussels There s only one dreissenid species in this lake: D. presbensis

45 and here s an example of the two close cousin parasites There s a ciliate that is a parasite in D. presbensis in Macedonia There s a different species in same genus that is a parasite in D. polymorpha in North America Ophryoglena n. sp. Ophryoglena hemophaga

46 and here s an example of the two close cousin parasites There s a ciliate that is a parasite in D. presbensis in Macedonia Ophryoglena n. sp. So save money by understanding this local one. before spending lots of overseas travel money to study this one There s a different species in same genus that is a parasite in D. polymorpha in North America Ophryoglena hemophaga

47 .and now continuing on our countdown of ideal characteristics of a candidate parasite

48 IT IS LETHAL AND RAPIDLY SO 5

49 IT IS SELF-PERPETUATING FOLLOWING INITIAL INTRODUCTION 4

50 IT IS SELF-SPREADING WITHIN WATERBODIES 3

51 IT CAN ACHIEVE >99% KILL 2

52 IT IS HOST SPECIFIC TO DREISSENIDS 1 THERE IS SIMPLY NO CHARACTERISTIC MORE IMPORTANT

53 TAKE HOME MESSAGE Will there ever be lake-wide biocontrol of dreissenids in North American waterbodies? Don t give up on the use of parasites for that purpose, as they can have long-term devastating impacts on naïve host populations. To achieve this goal, the outside the shell solution will likely involve exposing our North American dreissenid populations to a parasite they have never ever encountered before a parasite from a distant related dreissenid species found outside the native range of the zebra mussel or quagga mussel, as for example from Dreissena presbensis in Lake Ohrid, Macedonia