Studies continue at Hammonton Lake
HAMMONTON—Since 2020, two scientists from Stockton University—Dr. Emma Witt, professor of environmental studies, and Dr. Aaron Stoler, professor of environmental science—have, along with their students, been conducting various studies at Hammonton Lake.
Witt said that Hammonton’s Lake Water Advisory Committee chairperson Dan Bachalis first contacted Stockton regarding studies related to coliform bacteria in the lake and “trying to get those under control.”
“They had been having high school students out there, taking water samples every summer since 2013; they had a lot of data, and it had been several years since anybody had been sampling the lake regularly. I had most of the stuff that we would need to do the water quality sampling, and then Dan hooked us up with the wastewater treatment plant folks to do the coliform sampling. I was able to get the water quality sampling back up and running,” Witt said.
Witt said that another aspect that Bachalis requested as a survey of the lake’s aquatic vegetation, which is Stoler’s domain.
“Anything related to lake quality is inherently going to be tied to the biological food web of the system. My goal was to do an initial survey of all of the plants and invertebrates in the lake ... If we’re going to find changes, it’s going to be in the bottom of the food web. We went out, and we did a massive survey in 2020 and another one in 2021 of all of the vegetation in the lake and all of the invertebrates in the lake as well,” Stoler said.
Stoler said that his team “found interesting things.”
“There are a lot of things in that lake that are not supposed to be there. They’re definitely invasive, meaning that they are there, they’ve taken over and they’re in high abundance. We think that they are probably negatively impacting the abundance of native species. To be clear—from a scientific standpoint—I won’t call these organisms bad, and I won’t say that they’re the reason why lake quality would be negative; they’re just not native species,” Stoler said.
Among the invasive species were the banded mystery snail, zebra mussels and Asian clams.
“This is essentially the triad of invasive mollusks, and we found them throughout the lake. Zebra mussels not so much—I think we found maybe one instance—but Asian clams were in high abundance, and we also found the banded mystery snails in high abundance,” Stoler said.
Stoler said that the abundance of mollusks is “one of the weird things about Hammonton Lake.”
“Typically, at low pH—as is characteristic of many Pine Barrens aquatic systems—organisms cannot form calcium-based shells. It’s very difficult. These snails, these Asian clams, they all have calcium carbonate shells ... I don’t know why we’re seeing so many mollusks in this lake relative to other lakes,” Stoler said.
Witt continued, noting that Hammonton Lake does have a higher pH level than that which is normally found in Pinelands streams—which are more acidic because of vegetation.
“Rainwater is naturally acidic. When it passes through a lot of the Pine Barrens forests, it’s going to become more acidic as it goes through the conifer canopies, and, with the needles falling, all that water’s going to percolate through the needles, and, especially in the cedar bogs, there’s a lot of acid in the vegetative system,” Witt said.
As that vegetation decomposes, Witt said, acids are released, which lowers the pH of the water.
“In most coniferous systems, you’re going to have a lower pH. Plus, the soils here are poorly buffered, so there’s not a lot of calcium or carbonate in our soils to raise that pH like there would be somewhere where you have a limestone bedrock; we’ve just got straight-up sand for hundreds of feet. There’s just nowhere for the pH to readjust,” Witt said.
Stoler said that acids leach out of plants naturally, and Pinelands plants have “their share of acids.”
“Couple that with a different soil composition that doesn’t have the buffering capacity, and a variety of factors will culminate in a lower pH lake. It’s just unclear to both of us, at this point, why Hammonton Lake has a higher pH; not that that’s necessarily bad, it’s just that it’s leading to the ability for organisms like these snails to stick there,” Stoler said.
Witt said that water samples were taken weekly throughout the summer, but getting to the lake during the fall semester has been a bit of a challenge.
“I’ve kind of paused on the water sampling but I expect that to pick back up in the spring semester, because I’ve got a project student lined up to do it ... In the past, when we were relying on high school students to do the sampling—which I think that’s great—they were really only available in the summer. Being able to add in the winter sampling and trying to make that more regular, getting back out there in the winter, and getting a more whole picture of what’s happening, seasonally, might help,” Witt said.
To assist in the study, Bachalis said that the Lake Water Quality Advisory Committee had held off on its typical herbicide-spraying regimen.
“We used to follow a regimen of spraying every other year. We changed that to spraying half of the lake one year, half the next and then letting the lake rest two years; that’s our current regimen in the lake management plan. Last year, we hit pause on that since they’ve been studying the lake so that they can study it under fully natural conditions without the intrusion of herbicides and things that will upset whatever’s going on normally,” Bachalis said.
Bachalis said that, at the committee’s November 9 meeting, the decision was made to still postpone spraying.
“We want to continue that, just letting the lake be the lake, let Stockton continue to study the lake and all the various impacts from unfiltered, uncontrolled stormwater, uncontrolled E. coli and animal feces coming into the lake, salt intrusion from roads over the wintertime and that sort of thing, and not spray the lake this coming spring,” Bachalis said.
Witt discussed the future of the study.
“I’d like to try to figure out what might be going on out in the watershed that’s impacting this, so maybe starting to do some storm sampling in the areas that feed into Hammonton Lake, and maybe start sampling a couple other areas. Right now, we’re sampling near Fowler’s Creek, near where Hammonton Creek comes into the lake near the Canoe Club, but that’s really the only input area that I’m sampling and I’d like to see other areas where streamflow comes into the lake, if they have similar issues or if it’s specific to Fowler’s Creek. That does seem to have different water quality than the beach area of the lake and over near Sail Lake, where I do the sampling,” Witt said.
Witt said that she would still like more answers regarding the coliforms.
“Where’s it coming from, and how do coliforms really work in a lake? I’m not really an aquatic microbiologist, but I did really enjoy working at the wastewater treatment plant with the students and learning how to run them, seeing the different numbers and trying to figure out what might be causing that problem. It’s kind of a pain to try to figure out—is it all fluxing in when it rains, or DNA analysis, because of how sterile you have to keep everything—but I do still think it’s an interesting thing to think about,” Witt said.
Stoler noted that one popular local theory regarding the coliform may not be the source at all.
“People are pretty quick to blame the geese on the shorelines ... The geese are just eating grass that would normally die, decompose and eventually go into the lake anyway, so all the geese are doing is short-circuiting the nutrient cycle there. They’re pooping stuff out into the lake, but they’re just pooping the grass that they’re eating next to the lake. It’s not as if they’re bringing a whole bunch of waste from Canada and bringing it to Hammonton Lake; they’re just eating the grass that’s already around the lake. It’s almost certainly not geese,” Stoler said.
“The Fowler’s Creek results clearly show that that’s a really high E. coli area after a rainstorm. The beach, even though it spikes after a rainstorm, it clears up fast. If the geese were fouling the beach area, we’d have E. coli spiking all the time. It’s coming into Fowler’s Creek, and there’s a major stormwater that dumps into Fowler’s Creek, all the way across town back to Wilbur Avenue,” Bachalis said.
One possible source, Stoler said, may be the high abundance of the banded mystery snails.
“They have a tendency that, when they die, they stink—and that could be one source of E. coli, too. On the biological side of things, we’re investigating that,” Stoller said.
Witt said that the water quality in Hammonton lake is not “necessarily bad.”
“Certainly, we saw a couple of coliform spikes this summer, but I think you’re going to find that in most any other South Jersey lake. The numbers I see, I wouldn’t say that the water quality is bad, but it does have some non-Pinelands characteristics—but you would probably find those in almost every other Pinelands lake, just because the stopping of the streams is going to change the water a lot,” Witt said.
There is no pristine, natural way that Hammonton Lake is supposed to be, Witt said.
“Hammonton Lake is not supposed to be there; it’s a completely manmade lake. So, ‘healthy’ is going to be a relative term, and it’s going to be healthy based on what we, as people, want to use it for. The healthiest thing, from an eco-standpoint, might be to put it back into a bog or a wetland, but we don’t want to do that,” Witt said.
Stoler echoed Witt’s sentiments.
“I think that any ecologist will say that the easiest thing you can do to improve any lake is to leave it alone and stop bothering it, and it’ll fix itself. The problem is, of course, that they want to use it at the same time,” Stoler said.
Witt commented further.
“If they wanted to open the lake back up to swimming—my understanding, in talking to Bill Parkhurst and a couple of the other folks on the committee is that there used to be a beach there; that grassy area where the geese hang out used to be a beach with lifeguards—the Department of Health is going to mandate coliform testing. If we were to be able to say, ‘this is where the coliform is coming from, and this is how we can lower that’ it might be easier to do that, if that’s something that Hammonton wanted to do,” Witt said.
Bachalis acknowledged that swimming at the lake “has always kind of been the big focus.”
“After seeing that the beach isn’t the most polluted area of the lake and the bacterial levels go down pretty rapidly after a couple of days, I’m hopeful about our eventually being able to do that if we can control the influx of bacteria, particularly through Fowler’s Creek ... Whether the town pulls the trigger on hiring a lifeguard, renovating or remediating the beach area so that it’s a nice area and putting in the ropes and everything else, coming up with a fee structure, from a lake management perspective, it’s irrelevant,” Bachalis said.
Bachalis said that the goal is to get the lake water quality back to a level where such discussions can actually be had.
“Even if we say that we don’t want to spend the money on it or we did survey and the community doesn’t really want to use the lake that way, it won’t matter. At least we’ll know it’s clean enough so that if somebody does go swimming on their own—which maybe you shouldn’t do—or falls out of their boat while they’re fishing or something, they’ll be able to feel safe if they inadvertently swallow a little water. That’s where I want to get the lake to, because it’s a good place for the lake to be,” Bachalis said.
Regardless, with the water quality where it currently is, Witt said that activities like fishing and kayaking remain unaffected.
“We love Hammonton Lake; I like to go kayaking on it, people love to fish on it and people like to live near it ... Healthy is going to be relative to the uses that we, as people, want for it,” Witt said.
Additionally, Stoler said that studying Hammonton Lake provides greater understanding of similar ecosystems.
“Hammonton Lake is along the lines of what lakes in the Pine Barrens could become, should development continue. It’s a great window to what lies in the future, but it’s also a way that we can explore ways of making our resources sustainably used by humans. If we can figure out what’s going on in Hammonton Lake, we can help other lakes around the region in their process of development,” Stoler said.
Witt explained further.
“One thing that is slightly unique about Hammonton Lake that you don’t always see is the level of development around it. A lot of our Pinelands Lakes are either going to be like Heritage Lake and Patriot Lake, down here in Absecon and Galloway, which are surrounded by parks but don’t have a lot of streams flowing into or out of them, but Hammonton Lake has at least two or three going into it and one of those streams drains most of the town of Hammonton—and the town of Hammonton is fairly big. Understanding the urban dynamics of the lake is helpful. You just don’t see a lot of that; Atsion Lake isn’t developed, Batsto Lake isn’t developed,” Witt said.
During the course of the study, Witt said, the Lake Water Quality Advisory Committee has been “amazing to work with.”
“They’re great, and it’s so nice to have people who are interested in learning more about what’s going on,” Witt said.
“When we find an association that is just generally interested in water quality and sustainability, I think scientists get really excited about that. It means that we have a place where we can go where people are supportive of general research, and that means that we can study Hammonton Lake with a general intention to understand the rest of Pine Barrens lakes, that Hammonton Lake is unique in many ways but it’s also not unique in many ways ... It’s so great to find an association that will willingly open its lake up to research,” Stoler said.
Both Stoler and Witt said that they intend to continue studying Hammonton Lake.
“What you’re seeing is two scientists embarking on a much longer-term study of the lake, trying to understand a grand picture of the lake from just a few puzzle pieces that we currently have. As most environmental science works, we think long-term. We don’t come up with solutions right away; we can’t usually pinpoint any one particular source. We appreciate that Hammonton is letting us use their lake as a classroom research case, where we can take students over multiple years and have them build up more and more pieces of the puzzle to help us understand the lake in its entirety,” Stoler said.
Bachalis said that he is “honored that Stockton wants to work on our lake so much.”
“We get so much back from their studies, and they’re enthusiastic about doing other studies and more studies ... The collaboration with Stockton has opened our eyes to a larger universe and shown us that Hammonton Lake is a real draw for not just tourists and fisherman but researchers. They love it because it’s a self-contained lake, it’s very different from other lakes in the area, and it’s a great natural laboratory. We’ve benefitted from it, and I think we’ll continue to benefit from it. I can’t wait to hear what else they’re finding out,” Bachalis said.