Kristine Bonnevies hus
High fishing pressure tends to lead to proportionally fewer old and large individuals in fish stocks. It is feared that these demographic changes make the fish stocks more sensitive to climate variability and change. Statistical analysis of long-term survey data on cod eggs throws new light on the possible mechanisms.
In March 2016, a Memorandum of Understanding for Seas of Norden Research School (SEANORS) promoting collaborative marine research and training in the Nordic countries was signed by the rectors of 9 Nordic universities.
Spawning time and location are important factors affecting the reproductive cycle for migratory fish by potentially affecting offspring survival and growth. We examine this relationships by using a drift model for early life stages (eggs to age 1) of the Northeast Arctic cod combined with empirical estimates of spatial variation in mortality at two different life stages (Langangen et al. 2016).
The Marine Group of CEES was created in august 2005 as a platform where people with common interest meet and exchange ideas. In 2015 we were about 20 post-docs and PhDs financed on project money. I think it is time after more than a decade to look at the success and failure of our group, generally share experience, and maybe brag a little.
Mass mortality events are events that cause elevated mortality that may reduce the population size over a short period. Such events are likely on the rise across the globe and for several taxa (Fey et al. 2015). We recently investigated how such events may affect the community of interacting species in the Barents Sea. For this investigation, we constructed a multi-species model of a key component of the Barents Sea ecosystem consisting of fish and zooplankton
It is notoriously difficult to estimate mortality rates for zooplankton populations in the open ocean. In a new paper, Kvile and colleagues demonstrate that mortality estimation can be improved using a statistical regression approach (SRA) that takes into account advection and spatiotemporal trends in recruitment. Using this method on Calanus finmarchicus survey data from the Norwegian Sea–Barents Sea, they find indications of increased mortality for the oldest copepodite stage pair (CIV–CV), possibly reflecting higher predation pressure on larger copepodites.
Growing evidence suggests that the telomeres’ length (a non-coding DNA sequence localized at the end of the chromosomes) is related to individual breeding performances and survival rates in several species.
The development of haddock embryos is highly impacted by oil exposure as discussed in a previous post. In a new study Sørhus et al. explored the link between transcriptional changes and developmental processes such as pattern formation and organogenesis. The question is to understand the abnormal development in fish.
A recently paper published in PNAS, members of the CEES Marine Group explore potential climate effects on Calanus finmarchicus, a key zooplankton species in the North Atlantic. The paper shows how the combination of shallow mixed-layer-depth and increased wind apparently increases chlorophyll biomass in spring, and in turn C. finmarchicus biomass in summer. These findings strongly suggest bottom-up effects of food availability on zooplankton, and highlight the need to consider climate effects “beyond temperature” when projecting zooplankton dynamics under climate change.
Marine phytoplankton contribute nearly 50% to global primary production, support zooplankton production and play a vital role in regulating Carbon sequestration. Phytoplankton productivity fluctuations are caused by various direct and indirect effects of temperature, the balance of which show large-scale geographical patterns.
Friday 11 December 2015, Kristina Øie Kvile has defended her PhD about the climate effects on Calanus finmarchicus dynamics with success.
Penguins are highly visible species for the public. Their life has been portrayed in many movies. Unfortunately they are also species impacted by climate change. In a recent publication a team led by Charles Bost used long-term data to relate the large-scale climatic anomalies in the Southern Hemisphere to the foraging behaviour and population dynamics of the king penguin.
Interdisciplinarity is a central focus for many funding agencies. The argument for this is that only with scientists working together that some of the major questions of today could be answered. In a recent paper, a collection of students and post-doc from the NorMER network explored the difference of perception of scientists in function of their discipline: social science or natural science.
Interdisciplinarity is often presented as the solution to answer some of the major questions of today. Master student Djuna Buizer reflected on the subject in a post.
The toxicity resulting from exposure to oil droplets in marine fish embryos and larvae is still subject for debate while at the same time worldwide energy demands have resulted in increased hydrocarbon extraction activity.
Opening the sea areas around Lofoten and Vesterålen islands for petroleum activities is a highly debated topic. One of the main concerns has been to what extent an accidental oil-spill may affect the ecologically and economically important species of fish that spawn in the area. We have investigate how an increased mortality event at the egg and larval stage in cod may affect the population.
This paper investigates the scope for resilience indicators to predict an upcoming stock collapse. We find that economic information, such as profits, may complement biological information when assessing the state of fisheries.
A fundamental challenge for European Marine Science is to deliver scientific impact, global leadership and sustainable blue growth for Europe in times of overexploitation, climate change and other anthropogenic stressors. The Marie Sklodowska-Curie Innovative Training Networks MARmaED project makes important steps to answer this challenge by connecting science, policy and people, thus transcending national borders, disciplinary barriers and sectorial divides.
Spatial Ecosystem models can be useful but need to be validated with data. Our study validates for the first time the spatial version of the commonly used Ecopath with Ecosim ecosystem modelling suite. We find that spatial distribution of fish species is well predicted by the model, but fishing effort distribution is not.
In this study we assessed the chances of recovery of the Baltic Sea cod stock and conclude that it will never come back to the status it had more than three decades ago and that the economic losses associated to this new baseline amount to 120 million euros per year.
Climate warming is known to affect predator-prey relationship and phenology. Less is known about competitive relationships specifically in a nonlinear framework. In a recent study, we studied this topic on…
The Ecosystem Approach to Fisheries Management has for many years been presented as the way to go to ensure fish stock productivity and has been adopted by many governments and international organizations. But to which extent has ecosystem information in fact been included in tactical fisheries management practice?
Many marine fishes experience tremendous mortality during their first months of life. Understanding the causes of this mortality and why it varies from year to year has challenged fisheries ecologists for more than a century. Part of the difficulty comes from the fact that many fishes have free-floating larvae. It is therefore difficult to follow a group of fish larvae over time in the field and investigate which factors cause mortality.
Since Hjort’s ground-breaking work, it is admitted that the survival from the egg to the first reproduction is an essential factor affecting the dynamics of fish populations (see post). Human activities around spawning ground may have an effect on the mortality of the younger age. One of such potentially risky activity is oil exploitation which is on the increase in the northern areas.
Much of our present knowledge on the ecology and behaviour of animals is derived from longitudinal studies of individuals using long-term datasets. The collection of such datasets requires the ability to identify individuals repeatedly over time, i.e. by individual markings. Here comes the problems for Penguins.