Rogowski main page

County Antrim, Northern Ireland

David Rogowski's Research Page

Email: david.rogowski(at)ttu.edu

Assistant Professor
Department of Natural Resources Management
Texas Tech University
Mail Stop 2125
Lubbock, Texas 79409-2125

Dept. phone: 806-742-2841
Direct: 806-742-6888 xt 227
FAX: 806-742-2280

Cuatro Ciénegas, Coahuila, México

Research interests

My research interests are fairly broad, but revolve around ecology and evolution, primarily in aquatic systems. In particular, I am interested in how organisms, and ultimately how populations respond to their environment. I am interested in the importance of biotic and abiotic factors in structuring populations and communities. Differential tolerances to stressors such as salinity, pollution, or even invasive species can have both direct an indirect effects within a community. How populations and communities respond to these stressors can provide insight into evolutionary processes. A good portion of my research has centered on the effects of stressors on aquatic populations and communities, and species habitat associations. My current research focuses on applied issues related to the conservation and management of aquatic resources.

Current projects

Ecology of Desert Springs
Currently my lab is investigating the ecology of desert springs in the west Texas, NM and AZ areas. At the moment we are concentrating on native springsnails in three locations: Diamond Y springs north of Fort Stockton, TX; Boneyard Bog Springs near Alpine AZ; and soon we will have a project at San Solomon Springs in Balmorhea State Park, TX. People in the Rogowski lab	Diamond Y Spring Preserve owned and managed by The Nature Conservancy

Arizona
Boneyard Bog, AZ Pyrgulopsis trivialis photo by Mike Cox, USFWS	Three Forks Springsnail, (Pyrgulopsis trivialis) The Three Forks Springsnail is a candidate species with a very limited distribution (2 springs near Alpine, AZ) and is under threat from habitat modification and alteration (elk wallowing and trampling by cattle), as well as an invasive crayfish (Orconectes virilis). Michael Martinez of the US Fish and Wildlife Service at the Arizona Ecological Services Field Office in Phoenix had conducted a species habitat association study, and we have just recently submitted the manuscript. A physid snail occurs within the same springs and it appears that there is an apparent habitat separation between the two snail species, with the physid snails being more abundant in warmer areas of the spring complex. Habitat selection and or competition between these two snails is an interesting aspect of the system that we are exploring further, as well as the potential effects of crayfish on habitat use and survival of both snails. Currently I am testing temperature selection of both snail species, and monitoring reproduction and other life history traits. Recently the springsnails just laid eggs in the lab (July 2009) see image below, and we now have juvenile springsnails. The Phoenix Zoo is working on maintaining these imperiled snails in captivity under the direction of Stuart Wells and Tara Sprankle. Between research in my lab and the Zoo we hope to develop proper husbandry and captive propagation techniques for the Three Forks Springsnails. P. trivialis egg casing with diatoms attached (~180 µm in diameter)
Northern crayfish (Orconectes virilis)	Northern crayfish The northern crayfish or virile crayfish (Orconectes virilis) is an invasive species that has become quite a problem in New Mexico and in Arizona. Arizona has no native crayfish, and many of the native species are suffering as a result of predation and habitat alteration by crayfish. I am interested in the population dynamics of these species and am conducting research on their life history with Scott Bonar of the Arizona Fish and Wildlife Cooperative Research Unit at the University of Arizona, and Sue Sitko of The Nature Conservancy. Our work is funded by the Arizona Game and Fish Departments Heritage Fund. I conducted a mark recapture study and investigated some basic life history characteristics of 3 populations within Arizona. The object was to use site specific life history information to construct population models with the goal of determining the feasibility of control and eradication of invasive populations of crayfish. This project has been completed and a final report submitted to AZ Game and Fish. I am in the process of converting that report into something more suitable for publication. As a side note: in the midwest (Illinois, Wisconsin, Minnesota) the virile crayfish is being threatened by another invasive, the rusty crayfish (Orconectes rusticus).

Ireland
River lamprey (Lampetra fluviatilis)	River lamprey My research on river lamprey (Lampetra fluviatilis) was my primary project at Queens University Belfast, and was funded by EHS. This work was continued by Richard Inger. Lamprey are in decline throughout Europe and little is known about them in Northern Ireland. We investigated the effects of lamprey on the fish community in Lough Neagh (the largest lake in the UK), and through stable isotopes we were able to determine that they are not anadromous (sea going) and instead remain in freshwater throughout their life cycle. We are using a recently developed Bayesian mixing model called "siar" (stable isotopes analysis in R) developed by Andrew Parnell at Trinity College Dublin to investigate lamprey diet in Lough Neagh. Lough Neagh is home to an endemic whitefish called pollan (Coregonus autmnalis) which supports a commercial fishery (Lough Neagh is also home to the largest eel fishery in Europe). There was some concern that lamprey were feeding heavily on this endemic whitefish, however preliminary work shows that they actually prefer brown trout (Salmo trutta) even though there is a much greater population of pollan than trout.
Pearl mussel (Margaritifera margaritifera) Nic and Davide	Pearl Mussels Pearl mussels (Margaritifera margaritifera) are in sharp decline throughout Europe, although in Ireland there are still some healthy populations. This project came about and is going forward because of an undergraduate student Nic (from Holland). Nic was doing a conservation biology internship here at Quercus and in need of an honors project. After a conversation with Jane Preston of Quercus and Dai Roberts of Queen's University Belfast, we came up with a great idea. There has been some controversy about the status of the pearl mussel in the Nore River, it has been classified as a subspecies (M. m. durovensis) by some, and by others as an ecotype - due to apparent morphological differences. I suspect that the morphological differences were more of shape continuum in response to differences in the environment (i.e. river water chemistry). So Nic took on the task of taking digital photographs of mussels from a variety of rivers in Ireland. He then created outlines of the overall shape (using program SHAPE) and we compared the mean shape across rivers. Another conservation biology intern from Italy, Davide continued Nic's work by quantifying the percentage of erosion within a shell (see image at left) using the freeware image manipulation program GiMP. Preliminary work looks promising and we are now working to obtain additional specimens from more rivers in Ireland and the UK. We have access to some historical specimens from 100-150 years ago and are interested in exploring any potential shape differences related to time and possibly pollution or changes in habitat.

Illinois
Mark Pegg holding a bighead carp	Asian carp I also worked on a small project at the Illinois Natural History Survey with a variety of colleagues looking at contaminants in Asian carp and linking differences in contaminants to diet using stable isotopes. Specifically we looked at the silver carp (Hypophthalmichthys molitrix) and the bighead carp (Hypophthalmichthys nobilis). Rogowski, D.L. D.J. Soucek, S. Johnson, J.H. Chick, J.M. Dettmers, M.A. Pegg, J.M. Levengood and J.M. Epifanio. 2008. Contaminant concentrations in Asian carps, invasive species in the Mississippi and Illinois Rivers. Environmental Monitoring and Assessmen. doi: 10.1007/s10661-008-0529-6 Collaborators: Dave Soucek - NHS, Mark Pegg -Univ. Nebraska, John Epifanio - INHS, John Dettmers - Great Lakes Fishery Commission, John Chick - INHS
polyembryonic physid snail eggs (i.e. more than one yolk in an egg)	Physid snails This is a project I was exploring while at the INHS in Illinois. I conducted some preliminary experiments - and at some point will write it up and would like to continue working with this model organisms. They are great for exploring life history and evolutionary questions I have also been investigating reproduction and mortality in physid snails. These snails are common throughout Illinois and occur in a variety of habitats. Streams in central Illinois are impacted by agricultural runoff, urban runoff, industrial waste, animal waste, and wastewater treatment outfalls. I have noticed some anomalies such as polyembryos, and malshaped eggs in some individuals. In addition to various impacts from pollution, snail populations also experience different levels of parasitism. Snails that have trematode parasites are unable to reproduce as these trematodes castrate their hosts. These populations are under different selective pressures (pollution and parasites) and I am interested in their response to these stressors. Are there differences in their life history and is it a result of plasticity or genetic changes in the population? cercaria (free living form of a trematode- these erupt from a snail host and have about 24-36 hours to find a fish host)

PhD research

I conducted my PhD research at NDSU under the guidance of Craig Stockwell. My primary study organism was the White Sands Pupfish (Cyprinodon tularosa). This is a state threatened species endemic to the Tularosa Basin in south-central New Mexico. The current distribution of the White Sand pupfish is limited to military controlled lands, the White Sands Missile Range (WSMR) and Holloman Air Force Base (HAFB) near Alamogordo.

Most of my PhD research focused on the ecology and life history traits of the White Sands pupfish. Additional information on the White Sands pupfish can be found here.

Pupfish life History
There are 4 disconnected systems that contain these unique fish. Two sites are presumed to be native (Malpais Springs, Salt Creek) and have been isolated since the last glaciation. The other two sites (Lost River, and Mound Springs) contain introduced populations. Environmental conditions (temperature and salinity) vary greatly between the different sites. In addition, the incidence and prevalence of parasites varies within and among the sites.

White Sands pupfish

I was interested in how environmental and biotic factors may have affected the evolution of these fish. One of the questions I attempted to answer was, are there life history differences between populations? I collected basic life history measurements on the fish such as weight (wet and dry weight) and length, percent reproductive weight, percent body fat, and percent reproductive fat. In addition I measured parasite load (trematodes), and investigated life history correlations with parasite intensities and sites of infection.

Parasites, pupfish, and salinity
I presented a talk at the 2001 Desert Fishes Council Meeting on research I conducted on a springsnail (Juturnia tularosa) whose occurrence coincides with parasitism in the pupfish. The abstract and some pictures are at: DFC abstract. This work was published in Rogowski and Stockwell 2006b.

Introduced Species
The Tularosa Basin is home to a variety endemic organisms. Many endemic organisms in the desert southwest are threatened, primarily through habitat destruction. However this is not the case with species in the Tularosa Basin, as most of the land is tightly regulated by the military. The greatest threat to endemic species in the Tularosa Basin is perhaps the introduction of new novel "alien" species. Some of these pose a threat to pupfish others do not. A large African antelope, the oryx was introduced around the 1940s. It is doing quite well, but does not appear to impact pupfish habitat. Feral horses have overgrazed, trampled vegetation and shoreline habitat in around pupfish areas at Malpais and Mound springs. Due to the impact of the horses, Mound springs was fenced off to protect pupfish habitat and the horses were removed in a large roundup a number of years ago.

oryx

Western mosquitofish
(Gambusia affinis)

Orconectes virilis

Introduced aquatic organisms include the mosquitofish (Gambusia affinis) and a crayfish species (tentatively identified as Orconectes virilis). The White Sands pupfish has evolved in the absence of any aquatic vertebrate, or a large omnivorous invertebrate such as the crayfish. How pupfish would respond to an introduced fish species such as the mosquitofish was unknown. At this time mosquitofish and crayfish currently are not in pupfish habitats, but they are close by on HAFB and WSMR.

In 2002 I completed an experiment investigating the effects of mosquitofish and crayfish on populations of pupfish using mesocosms (i.e. small wading pools). I presented the results at the 12th International Conference on Aquatic Species in 2003. My presentation is posted on their web site. This work was published in Rogowski and Stockwell 2006a. I also tested the reproductive salinity tolerance of mosquitofish. Salinity may be the critical factor in determining whether mosquitofish can become established in pupfish habitat, this work hasn't been published yet (some day)

Other Research interests

Freshwater Fishes
(note the links in the table below are no longer valid and I need to reload the pages on the server here at the TTU)
I am very interested in our native fish and invasive fishes, particularly non-game fishes. While at NDSU, I often went out collecting with Trevor Krabbenhoft, who is now working on his PhD at the University of New Mexico. I also managed to get out a few times while in the Champaign/Urbana (Illinois) area. While in Northern Ireland I sampled Lough Neagh from June 2006-October 2006.

Minnesota and North Dakota fishes (2002-2003)	Illinois Fishes (2004-2005)	Irish Fishes (2006)
Some larval fishes	Saline Branch - Champaign Co.	Lough Neagh
	Embarras River - Champaign Co.

Toxicology
I also have an interest in aquatic toxicology. For my masters work I concentrated on aquatic ecotoxicology working with mosquitofish (Gambusia affinis) populations. I investigated the effects of reduced genetic diversity (via inbreeding and population bottlenecks) on populations of mosquitofish chronically exposed to zinc. This research was conducted at the University of Louisiana at Lafayette under the direction of Paul Leberg. Other prior research included a study on dioxins in soils while working for the State of Washington's Department of Ecology, and most recently with invasive carp as noted above at the INHS.

Statistics
If some would have asked me as an undergraduate what one of my favorite subjects was, statistics would not have even entered my thought processes. My interest in ecological statistics was initially driven by efforts to understand and present data in a meaningful way. I have now come to appreciate statistics in its own right. I use a variety of commercial statistical packages (SAS, SYSTAT, JMP, CANOCO, PC-ORD) as well a number of freeware programs (Poptools, R, Program MARK) that I often find even more useful, check out the links listed below.

Advice to potential graduate students

Potential graduates students should check out Spencer Hall's web page on graduate resources at Indiana University in Bloomington. He compiled a nice page chock full of information and advice relevant to graduate students.

Additional Links	Some useful statistical links (all freeware - in no particular order)
North American Native Fishes Association	Program MARK a great program for mark/recapture data
Desert Fishes Council	The ordination webpage (a great introduction to ordination)
American Society of Ichthyologist and Herpetologists	Pierrre Legendre's homepage (some useful programs, RDA, CCA, etc...)
Ecological Society of America	Eco-Tools homepage
Southwestern Association of Naturalists	Poptools (an Excel add-in macro for matrix population models, and simulations)
The Nature Conservancy	ADE-4 (an ecological statistics program - it is now a statistical application package in R (see below) and no longer supported as a stand alone program)
University of Illinois at Urbana Champaign	R (a very powerful statistical computing and graphics program)
American Fisheries Society	Morphometrics - check out this site at SUNY Stonybrook , it has everything you need to conduct your own geomorphometric analyses
International Association of Astacology

Last updated 12 November 2009

All photos by D. Rogowski unless otherwise indicated