The most unique find to date was captured and released on Thursday 9/20/18. Identifying the mysterious specimen stumped the team, so images were sent to Sandy Hook NOAA fish lab staff for help. They replied confirming the identity of the creature, a Wreck Pond first (large image below), a juvenile mahi mahi! Mahi can be caught off the coast of New Jersey, however, finding such a small juvenile in Wreck Pond was certainly an exciting and special find for the team. If you are interested in participating in any of the remaining sampling events, please contact Julie Schumacher, julie@littoralsociety.org for more information. 
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While we may have lagged recently on our blog posts (our apologies) the Society has nevertheless been very busy at Wreck Pond. In mid-June, we started our river herring young-of-year (YOY) monitoring. As its name implies, this monitoring targets river herring born earlier in the year, and is complementary to our spring fyke net sampling: whereas the spring fyke sampling lets us know when and how many adult river herring are coming into Wreck Pond to spawn, the YOY monitoring lets us know if the spawning has been successful. The results of previous years’ work indicate that at least some YOY river herring migrate downstream in Wreck Pond in early summer. Because of this, the Society has expanded the timeframe of YOY monitoring to start in early June instead of September as was done the first two years of the survey. On July 12, 2018, the Society caught 142 YOY alewife. This is a fantastic catch considering the most we have ever caught for an entire season was five. Further, the following week we caught nine more. In addition to alewife, we have caught a number of other species including Atlantic silverside, stripped killifish, mummichog, northern puffer, and one short bigeye.  Short Bigeye, Pristigenys alta  Juvenile alewife, Alosa pseudoharengus
That’s a wrap folks! This morning we completed our last fyke net sampling event for the season. We would like to thank all of the volunteers who came out to assist us this spring. Your time and help is truly appreciated, as we could not do the job without you. While we are still analyzing all the data collected, we do know that we caught over 150 adult alewife this year, more so than in any previous year except for 2006. We also caught a large number of other species including gizzard shad, white perch, bluegill sunfish, pumpkinseed sunfish, brown bullhead, white suckers, golden shiners, striped killifish, yellow perch, a largemouth bass, black crappie, painted turtles, and one large ornery common snapping turtle, who - judging by his picture - will be happy to see us gone. But while the spring fyke net sampling is completed, our other work is just beginning. This summer and fall we will continue to seine for juvenile alewife. We also will be taking macroinvertebrate samples in the Wreck Pond Brook Watershed, and working on the construction of a fish ladder over Old Mill Dam.   Over the past month, the Society completed two more monitoring events at Wreck Pond. Over the course of these events, we caught approximately 70 alewife. A great catch. Mixed in with the alewife were some of our regulars (white perch, gizzard shad, pumpkinseeds, and bluegills), as well as a couple of lesser seen species (brown bullhead, American eel, black crappie, largemouth bass), and a few new catches for the year including a painted turtle and a common snapping turtle. Interestingly, the number of gizzard shad caught greatly increased in the 7th monitoring event. This increase in catch coincided with gizzard shad spawning period (late May through early June).  Alewife (Alosa pseudoharengus)  Black crappie (Pomoxis nigromaculatus)  White perch (Morone americana)  Painted turtle (Chrysemys picta)
The fifth sampling event is complete, and we can now add a further 29 alewife to our total catch for the year so far. In addition to the alewife, we also caught multiple white perch and gizzard shad (both common species seen in our net), as well as a pumpkinseed sunfish and several very large carp (see photo below). Well known to most freshwater anglers (often as a nuisance), pumpkinseeds (Lepomis gibbosus) are a freshwater species of fish in the sunfish family. They typically live in warm, calm lakes and ponds or in small rivers. They eat a wide varies of insects, as well as small mollusks and crustaceans, worms, and smaller fish. They are active throughout the day, often schooling with more pumpkinseeds and other sunfish such as bluegills. As an interesting defensive adaptation, pumpkinseeds have evolved a dark spot (eye spot) at the posterior end of their operculum (gill plate). This spot mimics the look of an eye of a larger fish as it is positioned further back on the body. When threatened by a predator, pumpkinseeds will often flare their gills to appear larger.   In yesterday’s post we highlighted some of the results from our fourth, and most recent, sampling event. In today’s post, we will be talking about what we caught in the event prior. The third sampling event took place from March 29th to April 2nd. No river herring were caught; however, we did catch a number of large common carp (Cyprinus carpio), each weighing around 10 to 11 lbs. Common carp are not native to NJ, or to the United States for that matter. They were first introduced to North American in 1831 by Captain Henry Robinson of New York who brought them over from France. In a little over 50 years, common carp had become established in waterbodies throughout the nation. In New Jersey, common carp are present in almost every lake, pond, river, or stream. They have a long lifespan, living anywhere from 12 to 20 years. They forage on the bottom sediments of waterbodies, using their fleshy barbels to taste for insects and other invertebrates. Yet they are largely non-discriminant eaters, often consuming vegetable matter in addition to insects (NJDEP). In addition to the common carp, we also caught one mirror carp (Cyprinus carpio carpio). The mirror carp is a variant of the common carp that is differentiated by its irregular, patchy scaling pattern. The difference in scales is the result of variants in two genes. Another notable catch during the third sampling event was of a chain pickerel (Esox niger). This was our first catch of this species in Wreck Pond.     This morning we completed our fourth sampling event at Wreck Pond. Our sampling data from prior years suggests that the majority of alewife that migrate into Wreck Pond over the course of a spawning season do so in one or more large waves, often occurring in April. This pattern was born out this past weekend, as we caught 36 alewife over the course of two days (25 the first morning and 11 the second morning). It is possible more would have been caught if not for the change in weather. A sharp temperature drop halfway through the sampling event followed by strong winds and rain, may have affected the alewife spawning run as many fish are known to alter their behavior due to changes in light, temperature, or pressure associated with storms. Despite the harsh conditions, we continued to sample. Only one golden shiner and one white perch were caught the remainder of the event. Golden shiners are a predominately freshwater fish that often prefer the quieter parts of the river. Interestingly, the golden shiner was caught this morning. Rainwater flowing into the watershed last night and this morning creating high freshwater flows may help explain its appearance lower in the watershed. I want to thank everyone who has volunteered so far, particularly those who came out this last event.     Underneath the Wreck Pond Railroad Bridge, the orange buoy is out of the water. This past Monday (3/19), the Society wrapped up its second Wreck Pond sampling event of the year. Unlike our previous sampling event earlier in the month, no river herring were caught. Further, only a couple fishes were caught throughout the event: five white suckers were caught Saturday morning (3/17), and two white perch were caught Monday morning. We believe it is likely that the harsh March weather impacted fish movement (as I write this, the fourth nor’easter of the month is barreling across the state). Throughout the net set, winds were blowing hard west creating upwelling and lowering inshore water temperatures. Ocean temperatures were in the low 40 degrees Fahrenheit, a temperature not preferable for river herring migration. Further, winds have been creating blow-out tides with little water remaining to support fish movement during low tide underneath the railroad bridge.
Earlier this month, we registered our first detection of a tagged alewife at the new culvert. Fish 548 was caught in the fyke net the morning of March 1st. She was tagged and released, and later detected at the entrance of the culvert 15 minutes before midnight. Her abrupt departure, may be an indication of fallback, in which the stress of capture and tagging resulted in her abandoning her migration. Keep a lookout for the orange buoy from March 29th to April 2nd when we will be out there sampling once again.
On the evening of February 27th, the Wreck Pond Sampling team, including local volunteers, set the fyke net up under the rail road bridge located just south of the Shore Road rail road crossing and adjacent to the pump station. The next morning, four fish were caught including one grass carp, two white suckers, and one white perch. Although the evening event yielded no catch, this morning on March 1, 2018 (drum roll please), we caught two healthy adult alewife river herring. All involved were elated and we immediately began to process the fish to ensure survivability. Once weighed and measured, the two individuals (one male and one female) were both safely tagged and released upstream.
This is the earliest the Wreck Pond team has caught river herring in their net. The species is typically observed once water temperatures are between 42 to 50 degrees Fahrenheit but ocean temperatures have been hovering around 40 degrees and we did not anticipate seeing any herring yet. At the time of capture, the temperature in the pond was recorded at 47 degrees Fahrenheit (39 degrees offshore). We will continue to monitor offshore buoy readings but it would appear that the herring can and do come into Wreck Pond when it is a bit colder offshore. One helpful hint regarding their potential presence close to shore are plunging Northern Gannets observed out at sea. Even though these birds are most likely feeding on bunker, it does make us wonder if schools of herring are mixed in as well.
With the upcoming Nor'easter expected to hit tonight through Saturday morning, the team is curious to see if more herring show up in the net pushed by the winds and exceptionally high tides associated with such a storm. We hope to brave the storm and continue sampling through Saturday, but if the orange buoy is gone, that means we either headed for higher ground or we lost our gear. See you after the storm! If you have interest in participating in any future sampling events, please contact Zack Royle, zack@littoralsociety.org While for most, the warm days earlier this week probably brought thoughts of sunny spring days spent at the beach or the park, but for us here at the Littoral Society, the warm days brought thoughts of one thing: river herring. River herring migrate into freshwater to spawn in early spring, with the start of their migration triggered by warming ocean temperatures. In anticipation of the herring run into Wreck Pond, we spent the past week installing antennas in the watershed. These antennas are used to track the movement of river herring previously tagged with passive integrated transponder (PIT) tags. Like a fish EZpass, when a tagged fish swims through or past an antenna, its tag number is registered on a computer along with the date and time. Our tagging work has already provided some interesting information on the alewives spawning in Wreck Pond: data indicate spawning alewives spend about 20-30 days in Wreck Pond, and are most active at night. In addition, two fish (Samantha and Bonnie) have been recorded spawning in Wreck Pond in multiple years. Next week we will be starting our fish sampling. Using a fyke net, we hope to capture adult river herring migrating into Wreck Pond to spawn. We also record information on all other species we catch. If you have an interest in helping to sample, contact Zack at Zack@littoralsociety.org. Stay tuned the next several weeks for more updates on this year’s monitoring.     |
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