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Spatial trends of benthic secondary productivity in the Arctic Ocean

Conference Paper · December 2014

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8 authors, including:

Some of the authors of this publication are also working on these related projects:

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Evaluating the cumulative impacts of human activities on the structure and function the trophic network of the estuary and gulf of St.LawrenceView project

Philippe Archambault Laval University

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Arny L Blanchard

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Howard M. Feder

University of Alaska Fairbanks 80PUBLICATIONS 2,677CITATIONS

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Dieter Piepenburg

Christian-Albrechts-Universität zu Kiel 148PUBLICATIONS 1,982CITATIONS

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Spatial trends of benthic secondary productivity in the Arctic Ocean

Rigolet, Carinne (1) , P. Archambault (1), J. Holstein (4), A. Blanchard (2), B. Bluhm (3), H. Feder (2), K. Iken (2) and D. Piepenburg (4)

A test example:

Step 2: Random Forests model

Objectives:

Step 1: Collection of Biological Data and

associated environmental data (input Data)

Step 3: Use of environmental

predictors

(1) Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski (Québec) (2) Institute of Marine Science, University of Alaska Fairbanks (Fairbanks, Alaska)

(3) Department of Arctic and Marine Biology, Faculty for Biosciences, Fisheries and Economics (Tromsø, Norway) (4) Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung (Bremerhaven, Germany)

1) Benthic biomass data (and associated environmental parameters) were gathered

from retrospective large datasets and ongoing studies, from published, unpublished

sources and online databases.

2) Geostatistical and modeling approaches (the Random Forest algorithm) are used to

correlate environmental variables with biological observations. The resulting model is used to assess benthic productivity distribution patterns in the Arctic ocean from predictor varia- bles.

Benthic secondary production is calculated from biomass and

abundances data using Artificial Neural Network model [1]

1500 stations (Fig. 1)

Environmental parameters

(depth, temperature, salinity...) are also reported for these stations

Sea Ice Concentration

(from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Mi- crowave Data [3])

Sea Surface Salinity

(from the Aquarius/SAC-D mission [4])

Sea Surface Tempera- ture

(from Advanced Very High Resolution Radiometer [5])

Bathymetry

(from ETOPO1 global relief model [6])

Fig. 1. Benthic fauna sampling locations

Our approach offers an effective tool to:

1) identify areas of potential high biological activity (ecological "hotspots").

2) facilitate the evaluation of marine protected areas and the development of ecosystem-based management approach.

3) show that data sharing and collaborations can be transformed into useful information

References:

[1] Brey, T. (2012). A multi-parameter artifivcial neural network model to estimate macrobenthic invertebrate productivity and production. Limnology and Ocea- nography: Methods.

[2] Breiman, L. (2001). Random forests. Machine Learning,

[3] Cavalieri, D. J., C. L. Parkinson, P. Gloersen, and H. Zwally. 1996, updated yearly. Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.

[4] Yueh,S.,Tang, W.,Fore,A.,Freedman,A.,Neumann,G.,Chaubell,J.,Hayashi,A (2012). Simultaneous salinity and wind retrieval using the cap algorithm for Aquarius.

[5] Casey, K.S., T.B. Brandon, P. Cornillon, and R. Evans (2010). "The Past, Present and Future of the AVHRR Pathfinder SST Program", in Oceanography from Space:

Revisited,

[6] Amante, C. and B. W. Eakins, ETOPO1 1 Arc-Minute Global Relief Model: Procedures, Data Sources and Analysis. NOAA Technical Memorandum NESDIS NGDC-24, National Geophysical Data Center, NOAA.

[7] Jerosch et al. (2013). Geostatistical mapping and spatial variability of surficial sediment types on the Beaufort Shelf based on grain size data. Journal of Marine Systems

Fig. 2. Example of benthic Arctic community

Fig. 4. Map of remotely-sensed data for several environmental parameters in the Arctic.

Image courtesy of the National Snow and Ice Data Center, University of Colorado, Boulder

Predictor variables used: bathymetry (Fig. 5a) and sediment properties [7]

(Fig. 5b). Sampling stations with available benthic biomass data are added in (Fig. 5a).

Prediction of benthic biomass distribution in the Mackenzie Shelf (Random Forests regression) from bathymetry and sediment properties is presented in Fig. 5 c).

Take home message:

Motivation :

In the context of global climate change, the Arctic system has experienced substantial and rapid changes with potential effects on marine ecosystem health. In this light, description of the current state of the Arctic's ecosystems is increasingly needed. In parallel, large and valua- ble historical databases existed in published and unpublished records from the Arctic that had never been synthesized.

Variables: Benthic Biomass and abundances

It is used to :

(1) model the relationship between environmental pa- rameters and response variables (i.e. productivity), and (2) predict seafloor secondary productivity from

environmental predictors.

Random Forests is:

- A machine-learning algorithm [2]

- It is an assemblage of a large number of classification or regressions trees with binary divisions

- Each tree of the Forest is grown from a bootstrap

sample of response variable. Each tree uses a series of rules to recursively split the dataset into binary groups in order to maximize differences in offspring branches (Fig. 3).

Predictors variables:

PP: Primary production

SST: Sea surface Temperature SAL: Bottom salinity

TEMP: Bottom temperature CHLA: Chlorophyll a

Ice cover Depth

Step 4:

Secondary productivity prediction and model validation (coming soon....)

Method:

1- Describe the spatial pattern of benthic secondary productivity in the Arctic Ocean from shared and public data

Fig. 3. Principle of the Random Forests (Figure by Horning, N.)

Prediction of the distribution of the benthic biomass in the Mackenzie shelf (Beaufort Sea)

Fig. 5 a) Fig. 5 b) Fig. 5 c)

We consider that benthic secondary production (i.e. the amount of organic material produced through time) may represent a useful, quantitative tool for the assessment of Arctic ecosystem health and functioning, mainly because:

1) It incorporates all of the information relative to the health status of a biological system (i.e. growth, reproduction, survival...)

2) It represents the cumulative responses of a biological system to its abiotic and biotic environment.

2- Show that sharing data could lead to 'productive' project.

See below the several steps of the study ...

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