Early Detection at the
Molecular Level !
By convention, early detection of invasive species including aquatic invasive species typically relies on visual observation of the species causing harm or the symptoms thereof. In many cases we visually observe swallowwort (Cynanchum spp.) growing on the land or perhaps we catch a northern snakehead (Channa argus) while fishing for pike. From an ecological function perspective we see for example, canopy dieback indicating a possible forest pest or we may observe changes in aquatic food web abundance indicating the presence an aquatic invasive species. Unfortunately and according to the invasives curve, by the time a species is detected and the public takes notice, the invasive is already populated and the management thereof becomes difficult at best. Genuine early detection means detecting the presence of a species before it has the opportunity to populate and cause irreplaceable harm to the ecosystem of concern.
Aquatic invasive species often pose a unique level of difficulty when it comes to early detection. Simply put, many aquatic animals are hidden beneath the water’s surface and the invasion curve becomes skewed. The use of environmental DNA may offer a unique solution to the early detection of aquatic organisms.
As aquatic animals such as fish swim through the water, they constantly release biological material into the water. Materials such as scales, mucus and waste contain genetic material specific to that species. It is this genetic material that can be detected within water samples and amplified to allow for the unmistakable identification of a species and alluding to its presence within the area where the water sample was taken.
Genetics is one discipline that has an abundance of terminology barely understandable by those non-geneticists; however some basics may pertinent here. Once detected the amplification of DNA is done with a polymerase chain reaction (PCR). PCR is a method where an enzyme (polymerase), amplifies a short specific part of the DNA (amplicon) in cycles. In every cycle the number of short specific sections of DNA is doubled, leading to an exponential amplification of targets. In qPCR, exactly the same procedure happens but with two major differences: first the amplified DNA is fluorescently labelled (usually with cyanine based fluorescent dyes) and second, the amount of the fluorescence released during amplification is directly proportional to the amount of amplified DNA. The higher the initial number of DNA molecules in the sample, the faster the fluorescence will increase during the PCR cycles. The result looks similar to a barcode found on almost all goods purchased at your local grocery store. This barcode holds an enormous amount of information specific to that product (species).
Click on image above to magnify
Over the next two summers the partners of the SLELO PRISM in cooperation with The Nature Conservancy and The Department of Microbiology and Immunology at Cornell University, will undertake a project to assess the feasibility of using eDNA as an early detection tool for aquatic invasive species. Over 400 water samples will be collected from four strategic locations along Eastern Lake Ontario and assessed using qPCR for the presence of certain AIS. Underwater video technology (UVT) combined with eDNA will also be used as a citizen science component to assess the validity of UVT as an early detection tool as well.
 The invasion curve. Adapted from Invasive Plants and Animals Policy Framework, State of Victoria, Department of Primary Industries, 2010.
Salmon River Restoration
In 2013, after completing a feasibility study, partners of the SLELO PRISM endorsed an initiative to restore portions of the Salmon River by 1) suppressing Japanese knotweed populations, 2) restoring treated sites by planting native seed and plants and 3) implementing a robust educational & outreach component. This three year commitment was completed in 2015 with the following results:
Based on the original project goal which was to suppress knotweed populations and given an estimated 35% regrowth of knotweed after three consecutive treatments at some locations, it is reasonable to conclude that we achieved a 65% suppression rate.
Site restoration ranges from moderate to good. Two monitored sites DOT-1 and DSR-2 show little or no knotweed regrowth and very good native plant and grass growth. This same observation is noticed at additional sites treated along the river. Site DSR-1 shows good suppression, but some knotweed regrowth.
In general, the Salmon River corridor appears much different than it did three years ago. As you walk sections of the river banks there is noticeably much less knotweed and people, especially the angling community seem to have greater awareness of Japanese knotweed.
Suppression Results and Field Observations:
- 8.68 total acres of knotweed treated a minimum of three times over a three year period.
- Moderate to excellent suppression at most sites.
- Eradication at only a few sites (no regrowth during the third year).
- Plant mortality at predominately shade sites was noticeably greater than at sunny sites.
- Stem injection delivery resulted in a more rapid “initial” die-off, but long term there were no observed differences in mortality between injected sites and foliar treated sites.
- Soil type played no role as there was no observed difference in mortality between sites with rock soils verses silty-loam soils.
Site Restoration Results and Field Observations:
- 51,500 sq. feet restored to native grass using annual ryegrass, perennial ryegrass and little bluestem mix at 21 locations.
- 20% live stake survival using native on-site plant materials.
- Tree seedling planting being pursued as supplemental restoration.
- Site restoration ranges from moderate to good. Two monitored sites DOT-1 and DSR-2 show little or no knotweed regrowth and very good native plant and grass growth. This same observation is noticed at additional sites treated along the river. Site DSR-1 shows good suppression, but some knotweed regrowth.
- First native plants to volunteer at upstream sites included; jewelweed, smartweed, ferns, grass and maple tree seedlings.
Education & Outreach:
- Presentations to key stakeholders including the New York State Department of Environmental Conservation, the SLELO PRISM Partnership and representatives of the Salmon River Fish Hatchery.
- Four hundred informational pamphlets were disseminated at multiple distribution points to include: tackle shops, fish cleaning stations, stores, overnight accommodations and at the main entry gate at the Douglaston Salmon Run property.
- Informational flyers targeting conservationists and anglers were posted at all DEC kiosks at fishing access sites along the river with permission from DEC.
- River steward efforts (person-to-person dialog) along the river reached out to a total of 65 anglers.
On behalf of the SLELO partnership, we would like to thank the numerous landowners who gave us permission to access their property along the river for without their permission, this project would have never taken place. We also wish to thank the NYS Dept. of Environmental Conservation, The NYS Environmental Protection Fund, The Salmon River Fish Hatchery, Millers Turf Inc., Niagara Mohawk, National Grid and the Village of Pulaski for their cooperation. Thank you to The Nature Conservancy staff whom supported many aspects of this project; including grant administration, field operations, data management & analysis, human resources and especially our seasonal employees who set afoot day in and day out.
To view a detailed Project Report visit our resources page on the top menu bar, path: resources – information sharing – download/reports.
821 Hemlock Trees Inspected for Woolly Adelgid
Hemlock woolly adelgid (Adelges tsugae), native to Asia, is a small, aphid-like insect that threatens the health and sustainability of eastern hemlock (Tsuga canadensis). Hemlock woolly adelgid (HWA) was first discovered in the United States in 1951 near Richmond Virginia, and has since spread throughout the northeastern US and into the Midwest. Decline and mortality of hemlock after an infestation typically occurs between 4 and 10 years.
HWA is currently observed in Cayuga and Onondaga Counties, which border the SLELO PRISM. This species is considered a “Watch-list” species, whose arrival could be detrimental to the ecosystems found within the PRISM. One area of special concern is the southern Tug Hill Region. Eastern Hemlock is ecologically important, as it is frequently found along exposed slopes, protected gorges, and streams.
During the 2015 field season, the SLELO PRISM’s (2-person) early detection team embarked on an intense effort to survey hemlock stands for the presence of the Hemlock Woolly Adelgid. The focus area was the southern Tug Hill region within the lower half of the PRISM region. Our two person early detection team inspected a total of 821 hemlock trees within fourteen of our Priority Conservation Areas, PCA’s. So far no adelgids have been observed. The SLELO PRISM’s early detection team will continue similar efforts in the future.
For more information please refer to the HWA Field Report found in the 2015 Field Reports page of this website.
Saving Native Ecosystems
By Caitlin Muller and Benjamin Hansknecht
When it comes to invasive species, it is sometimes hard to understand the true cost and toll they take on the world around us. What could be bad about plants imported to reduce soil erosion, for example? Other times it is clear as day, like when an invasive species dominates the forest landscape, prevents sport-fish from spawning, or is harmful to touch like giant hogweed. The truth is that an invasive species can be any plant, animal, or micro-organism that might cause harm to the environment, biodiversity or human health, even if they also have useful traits. Although some species are more prolific than others, a trademark of most invasive species is their ability to outcompete native species for food (and other resources) and dominate an ecosystem if left unchecked.Monotypic understory of Japanese stiltgrass (Microstegium vimineum). Elklick
Woodlands Natural Area Preserve, Fairfax County, VA. Photo by Ben Hansknecht.
49% of threatened or endangered species are in demise as the result of invasive species introductions . By pushing out native rivals, invasive species often disrupt food webs, alter the ecology of the local ecosystem, and can ultimately lead to the extirpation of other native species. It is a global conservation issue with large scale ramifications and one important question to address is why these species are so successful when introduced to new locations and environments.
By relocating living organisms to new habitats, it is frequently the case that their destination is outside the range of their native predators and diseases, two of the biggest restrictions on population growth. Without these limits, it is possible for species to rapidly reproduce and expand their populations, whether they are continents away from their native range or as close as the state next-door. In this way, invasives can completely displace native species and create monotypic stands, or monocultures. This environment decreases the biodiversity of the area and in turn disrupts the local food web. Negative impacts to the habitat and resulting decreases in biodiversity in turn produce decreases in ecosystem quality.
For example, Eurasian water milfoil outcompetes native aquatic plant species for space and nutrients. By outcompeting the natives and through shear abundance it creates low oxygen environments via decomposition where native fish and aquatic invertebrates have difficulty surviving. This in turn limits the food supply of organisms higher up the food chain which feed on these species.
Some invasive species impact health of animals, invertebrates, plants, and humans. Swallow-wort, causes a problem for livestock when injested. Goats, which are sometimes used in invasive species control, cannot ingest swallow-wort as it causes illness. Monarch butterflies will lay their eggs on swallow-wort plants, because it’s a member of the milkweed family, but when the larvae hatch they will not survive due to the host specificity of the caterpillars. Other plants are affected by swallow-wort due to its allelopathic tendencies. By releasing toxins into the ground, swallow-wort inhibits other native plants from establishing. Plants such as giant hogweed and wild parsnip can affect animals and humans. Both plants cause a burn through a combination of coming in contact with chemicals on the plants stem and sunlight. Giant hogweed by far has the most damaging effects through this reaction.
In order to prevent decreases in biodiversity and maintain conservation value of our favorite outdoor places, invasive species awareness, prevention and management is important for all flora and fauna that depend on native systems including for posterity.
Partners of the SLELO PRISM continue to make progress towards the objectives and goals of our Strategic Plan. By working collaboratively we achieved the following in 2014:
Our partners continued efforts to restore the Salmon River and Salmon River Estuary by suppressing 86% of Japanese Knotweed populations and began restoration work by planting native grasses within the disturbed areas along the river corridor.
Our partners have significantly reduced the human health threats posed by Giant Hogweed by treating 61 sites and completely eradicating 14 sites.
We continued to restore over 50 acres of globally rare Alvar communities along the Eastern Lake Ontario coastline by suppressing Pale Swallow-wort and promoting native succession.
We have teamed up to protect our freshwater resources, wetlands and fens by supporting hands-on citizen science based control efforts, pathway mitigation and environmental DNA sampling. This includes hand-harvesting of 85.5 cubic yards of water chestnut plants and treating an additional 215 acres on the Oswego River.
Encouraged the development of biological controls for Water Chestnut (Trapa natans) and Pale Swallow-wort (Cynanchum rossicum).
Assisted with the release of a biological control (Galarucella spp.) to suppress purple loosestrife and maintain the native plant composition of the Lakeview Wetland complex.
Together we have completed early detection surveillance on ten priority conservation areas along with one rapid response to pale swallow-wort on the Limerick Cedars preserve.
Through a collaborative effort we reached over 550 individuals through a combination of educational and outreach initiatives targeted at invasive species that affect our forests, lands and waters.
Nice Work Partners!
Land Disturbance & Terrestrial Invasive Species
On my daily drive to and from work I have often noticed a relatively small patch of Japanese Knotweed (Polygonum cuspidatum) in the southeast corner of a nearby intersection. My previous disregard stems only from the fact that this small patch does not lay within one of our PRISM’s identified priority conservation areas (PCA’s).
In a more recent drive by of this same site, I noticed a small bulldozer clearing, or should I say grading the land. The topsoil, about 20 cubic yards was being staged along the south end of the lot and being that the entire site was covered with knotweed, certainly the topsoil was full of seeds and cuspidatum propagules.
After pondering the demise of the topsoil throughout the workday, I toyed with the idea of stopping after work to inquire as to what plans they had for the topsoil, after all topsoil is a sought after commodity. Too late, all the equipment and topsoil were nowhere to be seen.
Often overlooked in our discussions of invasive species pathways and mitigation is the idea of land clearing and infrastructure development, even on a small scale, and the translocation of topsoil contaminated with invasive plant fragments and/or seeds. I assume that the aforementioned “spoil” was used elsewhere to fill a need.
Let’s extrapolate using another species known for its high seed production (pale Swallow-wort (Cynanchum rossicum). At 2,000 seeds per square yard multiplied against an average 550 cubic yards per acre of topsoil, that suggests 1,100,000.00 seeds translocated per acre of contaminated topsoil.
In cooperation with our Canadian friends of the Ontario Invasive Plant Council, the SLELO PRISM Education & Outreach Committee will soon be pursuing a clean equipment protocol initiative that educates heavy equipment operators and will hopefully serve to identify contaminated topsoil and its translocation as a significant pathway for the spread of terrestrial invasive species. Identifying the need to manage contaminated topsoil is a good beginning, but must be followed with best management practice recommendations along with incentives to implement such practices.
The PRISM partners are confident that this initiative will serve to educate developers, engineers and heavy equipment operators on the need to better manage this pathway.
Rob Williams, PRISM Coordinator
Background on SLELO
Invasive species pose a serious ecological and economic threat in the St. Lawrence – Eastern Lake Ontario region of New York and indeed the entire state.
The St. Lawrence – Eastern Lake Ontario Partnership For Regional Invasive Species Management (SLELO PRISM) was formed in 2011 to combat the spread of invasives and mitigate associated threats. Our overall mission is to protect the natural and cultural integrity of aquatic and terrestrial areas in Jefferson, Oswego, Oneida, St. Lawrence, and Lewis counties from invasive species. Formally recognized by the state in 2011, our PRISM has made tremendous progress towards the prevention of new species and the management of existing species within the PRISM.
SLELO provides region-wide coordination for invasive species monitoring and management across the terrestrial and aquatic ecosystems within our 7,600-square mile PRISM region.
SLELO partners promote prevention, early detection and rapid response of invasive species through development and dissemination of educational materials and programs, documentation of species distributions, promotion of integrated habitat management strategies, and builds consensus for resource protection through partnerships with residents, institutions and agencies. Hosted by the Central Western NY Chapter of The Nature Conservancy, the SLELO PRISM has and continues to make significant progress towards invasive species management by utilizing the support and expertise of our partners.
- From early detection to rapid response and education, SLELO shares several goals with our PRISM partners.
- To focus immediate priorities, we have targeted several invasive species.
- We engage in several Projects & Activities throughout the SLELO region.
Invasive Species Program Coordinator Rob Williams, has engaged and rallied the SLELO partnership in a strong and focused way, one which will certainly help our PRISM to achieve our goals and objectives.