Wednesday, July 20, 2011

WPWA Survey for Aquatic Invasive Plants

Volunteers paddle among
nuisance pond plants
The Wood-Pawcatuck Watershed Association (WPWA) – in conjunction with URI Watershed Watch, RI Natural History Survey, and RIDEM – hosted a two-part invasive species workshop this past week. The first part of the workshop was held at the Coastal Institute at URI’s Kingston Campus on Thursday, July 14th from 6:00 to 8:30 PM. This portion of the workshop focused on educating volunteers about aquatic plant ecology, training them to identify the invasive plants, and discussing with them all that a survey entails. The second part of the workshop took place on Saturday, July 16th from 9:00AM to 12:00 noon at the Kingston Community Center at Asa Pond in South Kingston.
A view finder allows you to look
under the surface of the water
It was here that the volunteers reviewed and put into practice the identification skills they developed in part one of the workshop. The volunteers learned how to conduct the survey from boats, canoes, and kayaks. Anyone with access to a boat was welcome to join in the free survey. Plant identification guides and other necessary materials were provided free of charge. One such material involved in the survey were viewfinders, which are essentially see-through cylinders that allowed participants to view the submerged aquatic vegetation without any glare from the sun. Secchi disks were used to test the turbidity of the water. Volunteers gathered samples from the pond and placed them in bags labeled with their location and then marked that location on a map of the pond.
Native floating heart (white flowers)
Invasive species can have a significant impact on the ecosystems they invade and Asa Pond is no exception. While plants are generally considered beneficial to aquatic ecosystems, as they lower the water temperature through shading and prevent erosion, invasive plants can disrupt the natural ecosystem when they out-compete native species. According to Elizabeth Herron, who has worked for the URI Watershed Watch since 1992, the most common submerged invasives in the Rhode Island are – in decreasing order of abundance – variable leaf milfoil and fanwort. These species are particularly prolific because they can reproduce from fragments; in other words, a piece of one of these plants can grown into its own full-grown plant. Also, as may be the case with purple loosestrife overtaking native loosestrife and nymphoides peltata out-competing native floating heart, the bright colors of the invasives are more attractive to pollinators, which leads to more seeds being spread of the invasives and, thus, their proliferation.
Invasive yellow floating heart
Herbicides are the most effective means of combating the overabundance of invasive species and some have even been developed to specifically target invasives while leaving native plants unscathed. Unfortunately, herbicides can be very expensive and require a permit from the Department of Environmental Management; thus, they are not always a viable option for control of non-native species. Preventing the introduction of invasive species is generally the most desirable option; however, many people introduce invasives unknowingly and, education and outreach are important. Oftentimes, boats will introduce invasives when they are not properly washed. Similarly, plant fragments that remain in trail/bait buckets can lead to the introduction of invasives to areas where they’ve not previously been seen. Protocol for cleaning boats and buckets is currently being established. WPWA is currently working with groups in Connecticut to get support for invasive aquatic plant monitoring.
Variable Milfoil is an invasive species
The good news is that despite the heavy public use of Asa Pond, no invasive aquatic plants were detected during the survey. Still, throughout Rhode Island there is much work to be done in terms of preventing the spread of aquatic invasive plants, but through educational public outreach events such as the two-part workshop, progress can be made. If improvements are to be made it will require hard work on the part of volunteers and stakeholders throughout the watershed. If the turnout for this year’s workshop is any indication, there are many citizens concerned with the health of their watershed.

Invasive water chestnut


Elizabeth Gooding

Tuesday, July 19, 2011

Stingrays and Skates

Atlantic Stingray
Some people are scared of stingrays, some people like them, and then there are those very few people who live for stingrays. We had the opportunity to meet one such researcher from the University of Rhode Island and his Coastal Fellow who is following in his footsteps. John (Jack) Szczepanski was preparing for a joint meeting of ichthyologists and herbatologists in Minneapolis, when he and his Coastal Fellow, Peter Schooling (Marine Affairs - URI ’13) took a break from their preparations and research to share a brief lunch with us and discuss their interests and research.
Szczepanski gave us some basic details about sting rays to get us started. Stingrays are elasmobranches; like skate rays and sharks they have a skeleton made entirely of cartilage. Certain rays have reinforced jaws which allow them to consume hard species such as crabs, whelks, and snails. Stingrays have strong chemoreception and use their sense of smell to find their food. They store urea in their tissues to control salt intake because unlike most fish they don’t filter out the salt water, rather they store all the nutrients, which makes them taste bad and smell like ammonia. Stingrays are commonly used as lobster bate. They are also sometimes used as faux sea scallops in the Midwest and many species of rays are eaten in certain cultures. Electric rays, which are often found in Rhode Island, appear large and blobby and have an electric organ-muscle. The poisonous barbs on a stingray’s tail (that famously and tragically killed Steve Irwin) can break off and likely do not grow back.
Electric Ray (the red area is the
electric field emitted)
Generally, stingrays move inland during their remarkably long (11 month!) gestation period. An egg case is absorbed in the side of the mother stingray, who eventually gives a live aplacental birth. This type of reproduction is known as ovoviparity; in other words, the ray embryos develop in eggs that are held within the mother until they are ready to hatch. Some rays are rather large when they are born. For example, bull nose rays are generally between 18 and 30 cm at birth. Stingrays do not have a set breeding season. In contrast to stingrays, skates lay eggs, which is one of the major differences between the two otherwise similar species.
Szczepanski with the stingray
that stung him in the hand
on his honeymoon!
Large groups of stingrays (particularly the eagle ray and bull nose ray) migrate north from tropical waters in the summer. They are new but no longer uncommon in RI and have been seen in Narragansett Bay as early as May. Their migration this far north that early in the season may be indicative of climate change. Szczepanski believes their migration patterns may also be indicative of ecological changes because they are generally not commercially fished. Much of Szczepanski’s research takes places in Delaware Bay, which serves as a breeding ground for sharks that are sand-born and then spend the rest of their adult lives offshore. Delaware is very species rich, but comparisons can still be made to RI despite our fewer and smaller populations. Perhaps the most important correlation that can be drawn between the two water bodies is that they are both estuaries – breeding grounds/nurseries for numerous species.
Szczepanski with a stingray
on his honeymoon.
Szczpanski has gone out on many surveys to assess populations of stingrays (including one on July 20, 2010 while he was on his honeymoon and ended up getting stung in the hand!) While out on the boat, he measures the disk width from wing tip to wing tip and length from nose to pelvic fins, determines the sex of the stingray, and then checks for its stomach contents. Szczepanski then weighs and identifies the food from the belly of the stingray. Skates can have their stomach pumped to remove the contents for measurement. Little skates, which are common in Rhode Island eat a variety of food. Among other things, Szczepanski is trying to determine if their diets are more specific in Delaware, where they have a greater variety of food to choose from, than in Rhode Island. Clear nose skates, which are also common in Rhode Island tend to feed on squid, wheat fish, worms, crabs, shrimp, and more. Bull nose rays eat anything from whelks to mud snails and hermit crabs and sometimes even razor clams. Cow nose rays have strong jaws and plate-like teeth which are used for crushing. They, too, eat razor clams. Szczepanski believes that the mechanisms stingrays use to find food are – in order of importance – smell, sight, and electroreception.
Over the course of two years, Szczepanski will perform more than 20 surveys per bay (about one every month) in the Delaware and Narragansett Bays. He hopes to monitor how many stingrays are caught during each trip and their weights and species type. His work takes a serious dedication because he has almost no funding aside from his graduate studies research allowance. Szczepanski says he is grateful to have the cooperation of fishermen who allow him to examine the stingrays caught in their nets.

Elizabeth Gooding


The Changing Water’s Edge - 06/23/2011 – 8:30AM-12:30PM
Simulated LiDAR Survey
On June 23, 2011, experts, researchers, and governments officials came together to discuss the potential effects and implications of sea level rise. Every aspect of sea level rise and its results were examined during the four hour meeting held at Save the Bay in Providence. The meeting was composed of three major sections: maps and resources for local managers, case study presentations and discussions, and a view from the private sector.
Rhode Island does not have a plan to deal with sea level rise; however, it is crucial that one be developed, as the Newport Tide Gauge shows that the rate at which the sea level is rising is increasing. Planning is currently in Phase 1, consisting of data consolidation as well as the identification and quantification of vulnerable assets. Storm surge and spring high tide in Wickford can be viewed as precursors of impacts from sea level rise.
The LiDAR data was collected on May 2, 2011 and the product delivery is expected by the fall of2011. The deliverables should include raw point cloud data as well as classified points that specify ground, non-ground (trees, buildings, etc.,) water, and noise (ie. birds.) The existing data from 1997-2009 consists of maps of different scales, formats, and quality. Those maps have been compiled to make one accurate map available for viewing on ArcGIS. The information derived from LiDAR data can help standardize the accuracy of our understanding of the terrain of Rhode Island. It has such precise resolution, its margin of error is only +/- 6inches. The previous map had a margin of error of greater than +/- 3 feet.Recently a LiDAR(Light Detection and Ranging) survey of RI took place. The data from these surveys can provide a foundation for elevation data of the state, which can allow for predictions of areas that will be most impacted by sea level rise. LiDAR has a number of benefits. First of all, it is very precise, recording over 100,000 points per second. It has the ability to get multiple returns from a single pulse: in other words one pulse could detect a bird, the trees over which it is flying, and the ground beneath that tree canopy. The two major LiDAR products are digital surface models and digital elevation models, the latter of which can create bare earth digital elevation models(DEMs) which are used to calculate the areas impacted by sea level rise. The bare earth DEMshave 10 foot cell sizes and are hydroflattened, showing neither contour lines nor bathymetry.
A one foot sea level
rise in Wickford Harbor
LiDAR data will be particularly useful when examining the state’s tidal marsh areas. The total area and actual location of tidal marshes is important for a number of reasons. Tidal marshes are quite vulnerable to sea level rise and their locations and total area can change as a result of sea level rise. Many roads are blocking their retreat and if those roads are not moved, the marshes will inevitably be inundated. South County is a prime example of where this is likely going to be an issue. In order to model the potential effects of sea level rise, Kevin Ruddock of the Nature Conservatory presented models of how a 1 feet, 3 feet, and 5 feet sea level rise would impact different areas of the state. He depicted the scenarios using SLAMM (Sea Levels Affecting Marshes Model.) This modeling program takes into account inundation, erosion, overwash, saturation, and accretion on the topography of the state. It presents data on a1:12,000 scale.
Following the presentation and discussion of the compelling SLAMM maps, there was a discussion with North Kingstown town officials. After a short break, panelists from Bristol,Newport, and Warwick discussed the potential impacts of sea level rise in their respective areas. Diane Williamson, the Community Development Director in Bristol, discussed concerns regarding storm surge and the infrastructure in the Poppasquash/Hope Street infrastructure where culverts are being blocked by the receding seawall. There is a question of whether or not to repair the road, as it is at such a risk for flooding, it may be a waste of money.
A three foot sea level
rise in Wickford Harbor
In terms of flooding, she succinctly said it “hits you at home because it is your home.” Her talk was followed by a presentation by Newport Planning Director, Paige Bronk. He discussed how storm surge is also a concern in the area, as Newport lies well within a 100-year floodplain. Storm surge threatens retail business on Thames Street; however, due to the historic nature of those buildings, raising them remains controversial. Bronk called for a stronger state building code that will consider flooding. He also encouraged zoning relief for properties at risk of coastal flooding. Finishing this portion of the meeting, Janine Burke from the Warwick Sewer Authority discussed how the floods of 2010 presented a true challenge to the wastewater infrastructure in the city. She provided forceful pictures and statistics about how the Sewer Authority faced an unprecedented challenge from the floods; her office was evacuated on March30th and water levels there rose to six feet. The floods tested pumping stations that were “built like submarines,” completely wiping out six of them. The biggest impact of the floods could be seen in sanitary sewer overflows and electrical system problems. As a result of the floods, the wastewater treatment employees are now actively involved in emergency planning. Burke suggested that in planning for climate change, the following are major points to be addressed:energy efficient initiatives, renewable energy, consideration of future hydrology, and avoidance of construction in floodplains.
A five foot sea level
rise in Wickford Harbor
Finishing up the day, Sandy Taft, Director of US Climate Change Policy for National Grid discussed adjusting to climate change and addressing the risks associated with it. He said we must consider the impact of weather – wind, water, and temperature – on infrastructure. Taft suggested looking at long term threats and prioritizing based on how long each asset will be in place. In terms of flood types, he mentioned four types: coastal/tidal, fluvial/river, groundwater, and flash flooding and that they have been focusing on river flooding. While Federal Emergency Management Agency ranks areas in terms of risk as either low, medium, or high, the maps being used to categorize those areas may be outdated or based on historical events and therein lies several problems which we all face. LiDAR is a very helpful data source but National Grid found that sometimes it is not enough. For example, LiDAR cannot record inside a structure and therefore National Grid has had to conduct surveys of the equipment inside a building to determine if they will be flooded based on their elevation. Once flood implications are understood, several construction alternatives can be deployed which Taft described as avoidance, resistance, resilience, and reparability. Since National Grid is a UK-based company, Taft shared the different data sources that are made available in the UK versus the US and, as a result, the different internal design standards deployed.
Overall, the day was hugely informative for all of those involved. The speakers highlighted the extent to which sea level rise will have far-reaching implications, many of which are often not immediately obvious.
Elizabeth Gooding