northern sand lance

Lucas Jones presents his Masters Thesis research!

Lucas-HB-presentation
Lucas and Hannes celebrating the successful thesis presentation

Monday, November 22nd 2021. Big and heartfelt congratulations to Lucas Jones, who presented his Master thesis to his peers at the institute and colleagues national and international. Well done, Lucas!

A link to his recorded presentation will be posted here soon.


The UConn Department of Marine Sciences

Presents a Master’s Thesis Presentation by

Lucas Jones

B.A., University of Connecticut, 2018

4:00 p.m., Monday, November 22, 2021

Marine Sciences Building, Seminar Room 103

 

Using Low-Coverage, Whole Genome Sequencing to Study Northern Sand Lance (Ammodytes dubius) Population Connectivity in the Northwest Atlantic

 Northern sand lance (Ammodytes dubius) are key forage fish in Northwest Atlantic (NWA) shelf ecosystems, where they exclusively occur on coarse-grain, offshore sand banks. This patchy occurrence may result in genetically more fragmented, less connected populations, but traditional morphological or genomic approaches have so far been unsuccessful in fully resolving the species’ population structure and connectivity. My study pursued an alternative genomic approach, using low-coverage, whole genome sequencing (LcWGS) to address these important questions. I extracted DNA from 273 A.dubius specimens collected by collaborators from sevenregions across the species geographical range, from Greenland to New Jersey, USA. From LcWGS data, I identified 11,558,126 single nucleotide polymorphisms (SNPs) that allowed quantifying genetic differentiation between populations (FST), thereby revealing the genetic structuring of populations throughout the NWA. Despite the potentially homogenizing influence of the general north to south ocean circulation, I found a clear genetic break around Nova Scotia that delineated a northern from a southern A. dubius supergroup. Only within the southern supergroup, genetic distances increased with the geographic distance between sample sites. At the focal site of Stellwagen Bank (southern Gulf of Maine), A. dubius samples collected over several years (2014 – 2019) revealed small but significant temporal genetic differences that imply varying occupation of this offshore habitat by genetically different sand lance contingents. Inclusion of samples from the inshore congener A. americanus confirmed the clear genetic separation between both species and further determined that all sand lance caught on Stellwagen Bank are exclusively A. dubius. Overall, my work suggests the existence of two spatially distinct A. dubius populations with little ‘realized’ connectivity, which is critical knowledge to aid protection and management of offshore marine resources.

 

Major Advisor:                   Hannes Baumann

Associate Advisor:            Nina Overgaard Therkildsen

Associate Advisor:            Senjie Lin

Our sandlance work featured in the CapeCodFishermen

Reposted from TheCapeCodFishermen, April 28th 2021

By David N. Wiley

Bluefin tuna and striped bass crash through the waves. Seabirds wheel overhead and plunge into the water. Gape-mouthed whales rise from below. Schools of cod and dogfish hide below the surface.

While the convergence of such diverse sea life might seem accidental, those in the know thank a small, slender fish called a sand eel for the bonanza.

Also known as sand lance, these three-to-six inch forage fish are a main food source for many of the top predators in the Gulf of Maine and on Georges Bank, including some of the most commercially important species.

As their name implies, sand lance are tied to sand habitat, but not just any sand will do. To avoid predators, sand lance spend most of the night and parts of the day buried. When disturbed, they rocket out of the bottom, then dive head first and at full speed back into the sand.

As a result, their sand of choice has to be coarse enough to hold oxygen for the fish to “breathe” while buried, but soft enough to allow high-speed body penetration. One of the reasons Cape Cod is their Mecca is a band of perfect sand stretching from Stellwagen Bank along the backside of Cape Cod, past Chatham and up through Georges Bank. Whether you are a fisherman, whale watcher or seabird enthusiast, it’s this band of sand, and the sand lance that inhabit it, that makes the Cape special.

Sand and sand lance are the backbone of Stellwagen Bank National Marine Sanctuary, responsible for it being one of the top places in the United States for viewing marine life, and a centuries old, highly productive fishing ground. Yet while fishermen appreciate the importance of sand lance, little is known about their biology and most of the world does not know they exist.

To remedy the situation, a team of researchers led by scientists from Stellwagen Bank National Marine Sanctuary with partners from Boston University, Center for Coastal Studies, University of Connecticut, U.S. Geological Survey and Woods Hole Oceanographic Institution have been studying the forage fish to determine its importance and unlock some of its secrets.

One of the project’s first goals was to identify the sand lance spawning season. Using a specially designed and permitted small-mesh trawl, fished from Steve Welch’s F/V Mystic or NOAA’s R/V Auk, the team captured and examined sand lance. Thought to spawn from late fall through winter, several years of work demonstrated that sand lance on Stellwagen Bank spawn in a very narrow window at the end of November. Eggs are deposited on the seafloor and hatch after approximately six weeks.

Then things get interesting. Once hatched, sand lance are tiny, free-floating larvae for two to three months. Given this long free-floating period and the currents flowing over Stellwagen Bank, many sand lance born on the bank cannot stay there. So where do they come from and where do their offspring go?

To answer this question, the team used hydrographic modeling to backtrack to where free floating particles (like larval sand lance) would have originated prior to their sand settlement in March or April, and where drifting particles would end up two or three months after hatching.

It appears that larval sand lance settling on Stellwagen originate off the coast of Maine; years of highest sand lance abundance correspond to conditions that would have transported additional larval sand lance from as far north as Nova Scotia. The same modeling indicated that larval sand lance originating on Stellwagen Bank transport south to the Great South Channel and Nantucket Shoals (but not Georges Bank). In some years, currents moved them as far as New Jersey.

This is just another example of the interconnected world that creates a productive marine environment. Since few sand lance in the study lived past three years, the dependence on shifting currents to populate the bank could be one thing responsible for boom and bust years typical of sand lance abundance. The team is currently examining genetics of sand lance taken from throughout the Gulf of Maine, the mid-Atlantic, and eastern Canada, to gain additional insight into population structure.

Do boom-bust years influence the distribution and abundance of predators? The team investigated the association of sand lance with humpback whales and great shearwater seabirds by placing satellite tags on both species to track their movements.

Throughout the Gulf of Maine, tracking revealed that both species spend the vast majority of their time over sand lance habitat, and DNA from fecal shearwater samples showed sand lance to be the bird’s main prey. Surveys in Stellwagen also demonstrated a high co-occurrence of sand lance, humpback whales and great shearwaters.

Sand lance feed primarily from February to July, mostly on Calanus finmarchicus copepods. They stop feeding from August through October, with low levels of feeding from the end of November to January. Body growth and fat content show similar trends, with length and fat stores increasing from February to July. After July, the fish retreat to bury in the sandy bottom, conserving energy for spawning.

The team then turned its attention to the future of the valuable fish, something of extreme importance to fishermen. Ripe fish captured in November were strip-spawned on board the boats and transported to Connecticut, where eggs and larvae were raised in special tanks that allowed temperature and acidity to be manipulated to mimic future ocean conditions under climate change. Increased temperature and acidity had a dramatic negative impact on larval survival. According to Dr. Hannes Baumann, whose lab led the work, sand lance may be unusually sensitive to ocean acidification.

The future of sand lance was also a focus of team members Joel Llopiz and Justin Suca from Woods Hole Oceanographic Institution. They came to some worrisome conclusions.

The abundance of tiny C. finmarchicus copepods directly influences sand lance health: Abundant C. finmarchicus led to good parental condition and high reproductive success, while low numbers resulted in poor parental condition and poor reproductive success. Scientists have suggested climate change scenarios in the Gulf of Maine will lead to reduced abundance of this critical copepod resource. Adding to the problem was their finding that warm slope water coming through the Northeast Channel north of Georges Bank led to the death of overwintering reproductive adults.

With the Gulf of Maine warming faster than 99 percent of the world’s oceans, there is concern about the future of sand lance and its potential impact to the productivity of the Gulf of Maine, Georges Bank and other areas. While states with fisheries and other marine resources supported by sand lance cannot solve climate change issues, they can work to make sand lance more resilient to climate change. One way is to eliminate as many non-climate stressors as possible.

For example, in 2020 Massachusetts promulgated a rule limiting daily sand lance landings to 200 pounds. Rhode Island followed suit in 2021. These rules were designed to discourage the development of a commercial fishery for the species, such as the huge industrial fishery in Europe’s North Sea.

Since a commercial sand lance fishery does not currently exist here, adopting this rule by other states would be an easy, proactive way to make our waters, and the people who depend on them, more resistant to climate change disruption.

(Dr. David N. Wiley is the Research Ecologist for Stellwagen Bank National Marine Santuary. Funding for the project was provided by the Bureau of Ocean Energy Management, The Volgenau Foundation, Northeast and Woods Hole Sea Grant, International Fund for Animal Welfare, Stellwagen Bank National Marine Sanctuary and the National Marine Sanctuary Foundation. Dan Blackwood, Dr. Gavin Fay, Peter Hong, Dr. Les Kaufmann, Kevin Powers, Dr. Jooke Robbins, Dr. Tammy Silva, Mike Thompson, and Dr. Page Valentine contributed to the study)

Baumann-sandlance-470x504

[Lab news] Hannes and Lucas on a ‘genetic’ road trip

18 December 2019. Hannes and Lucas just returned from a spontaneous road trip to visit our good friends and collaborators at the University of Quebec in Rimouski (UQAR), Canada. We drove for over 10 hours (one-way) through snowstorms and icy voids to meet with Prof. Dominique Robert, who had collected sand lance samples from the Gulf of St. Lawrence and from Nova Scotia to be included in our new genomic study on the population connectivity of this species. Hannes gave a talk about our sand lance work and we saw a new institute in a new place, while frantically trying to stay warm amidst the brutal cold. Seeing the St. Lawrence in its icy, majestic beauty was a truly amazing experience.
Afterwards, we drove back through Maine and then repeated the fin-clipping of samples in Scituate at the Stellwagen Bank National Marine Sanctuary office, so we now have almost all samples in hand to start the DNA extraction and sequencing.
We are excited for the next steps!
Genomic-study-sample-overview

Sand lance samples to be included in the genomic study

StLawrence-Rimouski

Rimouski on the south shore of the mighty and icy St. Lawrence River on 12/13/19

lj-corinne-hb-rimouski

Lucas and Hannes listened to Corinne Burns talking about her PhD research at UQAR on 16 Dec 2019

hb-UQAR-talk

Hannes gave a talk about sand lance research at UConn

StLawrence-Rimouski-ice

The icy beauty of the St. Lawrence River

StLawrence-against-the-sun

Sun glistening on the ice on the banks of the St. Lawrence River on 16 Dec 2019

I-91-Vermont

Snow storm on the I91 in Vermont on 15 Dec 2019

snowstorm-night

Driving back through Maine on 17 Dec 2019 ... 6h of snowstorm

I-91-Vermont

Sand lance sample thawing to be fin-clipped

snowstorm-night

Hannes and Lucas fin-clipping specimens in the Stellwagen Bank NMS office in Scituate on 18 Dec 2019

[New Publication] Conservation Physiology publishes our first sand lance paper!

21 November 2019. We are excited to announce the Chris Murray‘s paper on the unusual, high sensitivity of early life Northern sand lance to acidification and warming has just been published in the journal of Conservation Physiology! This is the first publication of our extensive work on this enigmatic species.

Baumann-sandlance-470x504
Sand lance species play a key ecological role in most temperate to polar shelf ecosystems of the northern hemisphere, but they have remained unstudied with respect to their sensitivity to predicted future CO2 levels in the ocean. For the past three years (2016 – 2018), we have sampled and spawned with northern sand lance (Ammodytes dubius) from Stellwagen Bank National Marine Sanctuary and subsequently reared their embryos under factorial CO2 x temperature conditions to hatch and early larval stages. Our results were striking, in all years, high CO2 conditions severely reduced embryo survival up to 20-fold over controls, with strong synergistic reductions under combined high CO2 and temperature conditions. High CO2 also delayed hatching, reduced remaining endogenous energy reserves at hatch, and in combination with higher temperatures, reduced embryonic growth.

Indeed, given the observed effect sizes, northern sand lance might be the most CO2 sensitive fish species tested to date.


[Presentation] Hannes gives first NECAN webinar on sand lance CO2 sensitivity

sandlance-webinar
10 September 2019. Hannes started of the new 2019 NECAN Sea Grant Webinar Series with a presentation of our past years of research on the sensitivity of Northern sand lance (Ammodytes dubius) to ocean acidification and warming. The purpose of this webinar series is to highlight four projects funded through NOAA Sea Grant following the release of the NECAN paper published in Oceanography Magazine in 2015, “Ocean and Coastal Acidification off New England and Nova Scotia.”

Thanks to the more than 50 people who attended the webinar. If you have missed it, it’s accessible for free online. See below.


[Lab news] Chris defends his dissertation!

Chris_committee
Chris smiling after his committee congratulated him on his dissertation defense (f.l.t.r: Chris Chamber, Chris Gobler (via Skype), Eric Schultz, Hans Dam, Chris Murray)
6 December 2018. Today, the whole Baumann lab is congratulating Chris Murray today on his great day of defending his PhD. Chris presented the essence of his research on climate change effects on coastal marine fish to a packed audience in the seminar room, fielded an array of questions, and showed his deep knowledge of the subject during the subsequent discussion with his committee.
Well done, Dr. Murray! We are all so very proud of you!

bubbly-chris
The bubbly is opened in the Rankin Lab in true experimenter fashion!
chris-and-chris-rankin
Chris Murray and Chris Chambers in front of the sand lance tank in the Rankin Lab

[Research news] Sandlance are spawning on Stellwagen Bank again!

15 November 2018. After a stretch of foul weather kept us from going out to Stellwagen Bank last week, this time all the stars aligned for Emma and Mackenzie. Due to their success in catching spawning ripe Northern sandlance, we are now embarking on our third year of CO2 x temperature experiments on this species!


Mackenzie-Blanusa
Here is how Mackenzie Blanusa experienced her first trip to these enigmatic waters:
“This particular sandlance cruise was a day filled with firsts and is definitely a trip to remember. I accompanied Emma, Hannes’ postdoc, up to Scituate the night before the cruise and was given a rundown of what needed to be accomplished. I was a bit overwhelmed at first, because I’ve never dealt with sandlances before and did not know a lot about these fish. Nevertheless, I was eager to learn something new and was ready to help out wherever needed.

The goal of the sandlance cruise was to collect running ripe males and females to do a fertilization via strip spawning. Emma and I were a bit doubtful at first because we got less than 10 sandlance on the first two trolls. However, things got much better by the afternoon, and our most successful trawl caught 147 sand lance. I helped out with the fertilization and deploying the trawl, two things I have never done before. The most exciting part of the day was getting to see humpback whales. Usually they are in the distance but today they were right next to the boat. Everyone on board said that this never happens and it was very unusual so I felt very lucky to have seen whales at such a close proximity.”

Overall, the trip was a huge success and it was very refreshing to see everything go as planned. The only downside to the day was driving back home through a snowstorm. I later found out that there was a 73% fertilization success and we got 27,000 embryos for Emma’s experiment. I am very grateful to have gotten the opportunity to help out on this sampling cruise and am looking forward to doing this again in the future!


Sandlance-Nov2018-03
Emma on the makeshift spawning station for sand lance on board the RV Auk
Sandlance-Nov2018-02
Mackenzie strip-spawning sand lance on the ship

Stellwagen whales
Added perks of doing research on Stellwagen Bank …

Sandlance-Nov2018-04
Exactly 0.5ml of sand lance eggs (~ 600) were distributed into each replicate per treatment
Sandlance-Nov2018-01
Emma and Julie pipetting sand lance eggs