Cyanobacterial harmful algal blooms (HABs) can produce cyanotoxins. Upstream lakes and reservoirs featuring HABs have been documented as sources for downstream cyanotoxin presence, yet the persistence and behavior of cyanotoxins traveling downstream has not been largely studied. 

In partnership with the United States Geological Survey New Jersey Water Science Center (USGS NJWSC), the New Jersey Water Supply Authority (NJWSA) and the New Jersey Department of Environmental Protection (NJDEP), the Wu lab is investigating the persistence and transport of cyanobacteria and cyanotoxins across the Raritan Basin Water Supply Complex. This study integrates data from continuous water quality monitoring as well as discrete sampling events, and Solid Phase Adsorption Toxin Tracking (SPATT) passive samplers to evaluate how discharge and water-quality conditions influence cyanotoxin production, persistence, and transport. 

Habitat fragmentation often occurs when land uses, such as urban development, divide large patches of wildlife habitat into smaller, discontinuous patches in ways that restrict an animal’s migration from one patch to another. This is an especially prevalent issue in New Jersey, which is the most densely developed state in the U.S. and has an extensive road network.

The Wu Lab partnered with the NJ Division of Fish & Wildlife (DFW) for a long-term, state-wide habitat connectivity project to help solve NJ’s habitat fragmentation problem through the assessment of road-stream crossings, such as bridges and culverts. The goal of this project, which is a component of DFW’s Connecting Habitat Across New Jersey (CHANJ) program, is to better understand the role of road-stream crossings in fragmenting habitat for both aquatic and terrestrial species. The data collected will help illuminate whether fragmentation is occurring in key fish and wildlife habitat “cores” throughout the state and reveal potential migration corridors connecting these cores. These assessment results are used to identify restoration needs and improve connectivity where needed.

Microbial source tracking (MST) is the use of molecular and biochemical techniques to genetically identify coliform bacteria sources. Coliform samples are analyzed via polymerase chain reaction (PCR) and real time PCR (qPCR) for animal sources. These include human, Canadian geese, dog, deer, horse, and other common farm sources. Results will be correlated to surrounding farms to identify non-point pollution sources. Areas with human sewage pipes can also be reviewed to find if sewage pipes have been compromised due to recent natural disasters or pipe leakage.

Characterizing freshwater phytoplankton assemblages is crucial for the management and monitoring of New Jersey's drinking and recreational waters. Phytoplankton assemblages in New Jersey's waterbodies are poorly known, and there is no State list of phytoplankton taxa available. This study seeks to document the distribution and abundance of phytoplankton taxa present in the waters of New Jersey. Additionally, the study will aid in identification of potential toxin-producing taxa of cyanobacteria. 

Results of the study will address public health, economic, and environmental threats related to harmful algal blooms in New Jersey. 

Cyanobacterial harmful algal blooms (HABs) are algal blooms that have detrimental effects on native biota. Cyanobacteria comprise most of the HABs and are capable of producing various toxins such as neurotoxins (anatoxin-a, β-N-methylamino-L-alanine), dermatoxins (lyngbyatoxins) and hepatotoxins (microcystins). These cyanotoxins can produce symptoms ranging from diarrhea and vomiting to liver and kidney damage. Thus, monitoring of cyanotoxins in natural waters is crucial for public health and recreational water safety. 

We seek to identify potential toxin producing cyanobacteria taxa and to quantify cyanotoxin levels in natural waters. Cyanotoxins are quantified using the enzyme-linked immunosorbent assay (ELISA). Some study sites included in this project include Greenwood Lake, Hudson Estuary, Newark Bay, Passaic River, Hackensack River, Raway River and Raritan River.

The Musconetcong River, a major tributary of the Delaware River, is impaired for recreation due to the high abundance of fecal coliforms. The approved Total Maximum Daily Load (TMDL) requires a 93% reduction in nonpoint source fecal coliform loads and identifies potential bacterial sources as primarily agriculture, failing septic systems, and geese. In response to the TMDL requirement and to further characterize the impairments, Wu lab, partnerned with the Musconetcong Watershed Association, examined the water quality conditions across the watershed with a goal to identify the sources of fecal contamination and nonpoint source pollution via microbial source tracking (MST). 

The MST results indicated fecal contamination at the study area was mainly attributed to human, with sporadic substantial fecal contributions from cow, goose and dog. The highest fecal coliform loads in the study area were from tributaries; the catchment basins of these tributaries should be prioritized for future water quality restoration/enhancement actions. 

Greenwood Lake is a 1920-acre bi-state lake in Northeast New Jersey. The lake is a highly valued ecological and recreational resource for both states and has a substantial impact on the local economies. In addition, the lake serves as a headwater supply of potable water that flows to the Monksville Reservoir and eventually into the Wanaque Reservoir, where it supplies over 3 million people and thousands of businesses with drinking water. Although highly valued, the lake has been documented to experience declined water quality conditions, such as cyanobacterial harmful algal blooms (HABs). These poor water quality conditions have been attributed to elevated watershed-based pollutant loads, such as total phosphorus (TP). These issues continue to increase in frequency and affect the lake community more every year.

Tasked by the Greenwood Lake Commission, the Wu Lab is conducting a study to develop lake stormwater/nonpoint source managment inventories, to quantify vertical transort of nutrients that stimualte cyanobacterial harmful algal blooms, and to identify water quality conditions triggering cyanobacterial blooms.

To help better understand the way mercury enters and accumulates in aquatic animals (bioaccumulation), we study the factors that cause bioaccumulation and how mercury contamination spreads throughout aquatic food webs. We’ve focused on various turtle and fish species in select habitats throughout New Jersey – some of which are regularly eaten by humans and may present health risks when mercury is present.

In 2019, an ulcerative shell disease (USD) in Northern Red-bellied Turtles (Pseudemys rubriventris) was first reported in Salem County, NJ. This disease likely has a multifactorial cause, with some environmental component suppressing the immune system the turtles, leading to colonization by opportunistic pathogens taking advantage of the turtles' weakened state and forming the observed shell lesions. Some of the lakes where affected individuals were found were impaired by Cyanobacterial Harmful algal Blooms (HABs) in seasons prior, and so in partnership with the New Jersey Department of Environmental Protection (NJDEP), the Wu Lab investigated a possible connection between the USD and HABs. Phytoplankton community composition, cyanotoxin levels, nutrient parameters, and additional water quality metrics are being measured by the Wu Lab at several sites in affected lakes. 

With the current trends of climate change and eutrophication, cyanobacterial harmful algal blooms (HABs) are affecting both health of people and aquatic ecosystems as well as the health of our economy.  HABs have prompted beach closures against swimming, fishing, or boating and resulted in revenue losses befell the tourism industry. Taking into account the wide-ranging repercussions of HABs, as well as their increasing frequency, duration and magnitude, it is now abundantly clear that an economic and effective treatment technology is needed.  Ultrasound has a promising potential to control cyanobacteria cells and reduce cyanotoxins through cavitation and thermal effects. This project aims to test, develop, and optimize environmentally benign and economically competitive ultrasonic treatment technology that are capable of simultaneously and effectively removing phytoplankton and cyanotoxins to prevent and control HABs-induced, negative ecological, economic, and health impacts. 

There have been important improvements in the NY-NJ Harbor Estuary in terms of floatable debris, in particular thanks to the implementation of the Floatables Action Plan (FAP). NYC DEP has a well-established program to capture and remove marine debris (floating barriers, skimmer vessels, underflow baffles and screens) as well as source control programs (street sweeping, clean streets-clean beaches, adopt-a-basket, water-on-the-go, adopt-a-catch-basin and a B.Y.O campaign). New Jersey also has programs in place to capture and remove debris from the waterways (netting or screening facilities, street sweeping programs, and skimmer vessels to remove floatable debris from the Passaic River).

In spite of the progress achieved, floatable debris continues to negatively impact our region, and current efforts mostly deal with debris after the fact rather than attacking the root of the problem. This project will help characterize and identify sources of trash focusing on floatables entering local waterways and local conditions contributing to trash dispersal in order to target specific actions for reducing trash at the source; build on Columbia University’s 2016 data collection efforts in NYC (funded by NYC DEP); identify the most effective source reduction actions; educate local businesses and residents about trash impacts and solutions to encourage responsible vendor and consumer behavior and stewardship.

Wu Lab researchers have conducted street litter surveys at pre-determined sites in New Jersey. Following data collection, analysis and reporting, the results will be presented to the communities where the data was collected and work with local partners, municipalities and other stakeholders and a “Community Trash Reduction Toolkit” for local stakeholders will also be developed.

Species introduction is a leading cause of biodiversity loss. All around the globe, exotic species are replacing native species and altering ecosystem they invade. One major vector of species introduction is through discharge of ship ballast water. Thousands of ships travel around the world daily and can carry up to thousands of gallons of ballast water in order to maintain stability during voyage. Sea water along with marine creatures living in the water can be ballasted from a coastal port and be transported to the next destination of call where the water may be deballasted along with organisms it carries.

Zebra mussel is one of the many notorious invasive species introduced into North America via discharge of ship ballast water; zebra mussel invasion has caused detrimental ecological and economic impacts including the endangerment of native North American bivalves.

Dr. Wu and collaborator Dr. Junru Wu of University of Vermont have been working on the development of an ultrasonic device to control aquatic species introduction and invasion supported financially by the Sea Grant and the Great Lakes Restoration Initiative. Ultrasound is a sound wave above human audible frequency range. When directly encounter with aquatic organisms, ultrasound can form cavitation bubbles that damage/kill target organisms. The sound energy dissipates naturally as it travels in the water without causing secondary environmental impacts.

We identified a specific ultrasonic frequency that is most effective in controlling aquatic invaders and is developing a treatment system to control unwanted aquatic invaders before ballast water is released at coastal ports. Our goal is to stop hitchhikers in ship ballast water and to preserve aquatic biodiversity for future generations.

The springs included as part of this study are lotic systems where groundwater discharges to the surface. Spring water quality is influenced by the discharge and geologic origins of a spring. Biological indicators, such as aquatic macroinvertebrates, are used to assess the health of spring ecosystems due to their sensitivity to pollution.

Currently, there are no published studies on the aquatic macroinvertebrate assemblages in New Jersey springs. The objective of this study was to examine macroinvertebrate assemblages of New Jersey springs and to investigate the effects of geologic and hydrologic variables on macroinvertebrate community assemblages. Macroinvertebrate assemblages of six springs in New Jersey were studied from August 2014 to August 2015. This study found diverse macroinvertebrate communities in New Jersey springs and suggested that spring hydrology and geology affect macroinvertebrate assemblages. Routine monitoring is recommended for spring macroinvertebrate communities.