Terrestrial Biodiversity vs Marine Biodiversity- What's being observed more in Canada?
Background
I've slowly been creating Canadian-themed biodiversity projects over the past couple of years. Purely out of interest and to understand what my home and native land posts to iNaturalist.
The big project that is trying to be inclusive of all flora and fauna living on land and in water is found in my Biodiversity of Canada project.[1] My professional bias focuses my attention on ocean life, which is why I created my Marine Biodiversity of Canada umbrella project [2] and the individual ocean projects for each of Canada's three oceans.[3-5] With these projects, I could do what all good data-first folks do and started looking (playing? exploring?) and basic patterns of what the iNaturalist community observes (or not) in Canada.
Assumptions
It's fair to assume that most community-driven observations will be of organisms that live on land. The general public is mostly landlubbers, drylanders, and exploring on foot when casually being out and aboot. More specifically, water-proof technology is a luxury, niche item. Scuba-diving with a camera is an even more exclusive luxury skill. The fraction of ocean life that can be observed on shore is heavily influenced by the tides. The window of low tides throughout the year is pretty small which further restricts the slim chance most intertidal life will be observed. With all this in mind, the terrestrial observation bias was a given, but I still wanted to have some numbers to look at.
So, what are Canadians observing according to iNaturalist?
As of Mar. 8, 2024:
n= 13,012,012. The total biodiversity observations ([1])
n= 420, 696. The total marine biodiversity observations ([2])
n = 12,591,316. The total terrestrial biodiversity observations ([1] - [2])
97% of the biodiversity observations recorded on iNaturalist are of terrestrial flora and fauna. Or, a 30:1 ratio for how many terrestrial biodiversity observations are made to every marine biodiversity observation.
There's some grey to defining a species as either being terrestrial or marine. I was more liberal with including groups of species in the marine projects (e.g. waterfowl, some quadruped mammals, etc...). If excluded them from being classified as marine, then the terrestrial bias would be closer to 99% given more than 1/3 of the marine biodiversity observations are of seabirds!
It'd be interesting to dive a bit deeper into the taxonomic group bias and figure out which are the overlooked groups. I've already started exploring the one phylum that I've spent a couple of decades thinking about [6], but I have no doubt that organisms that have certain 'photographic traits' are going to be subconsciously selected for/against.
What does this mean?
These results probably shouldn't be surprising to traditional biodiversity scientists that operate independently of community science. The terrestrial > marine bias is often chatted about and not just in Canada. However, these numbers might be surprising to the iNaturalist community. If we consider that 1/3 of what we count as 'Canada' is ocean (land covers ~9.98 km2 and ocean is ~5.75 km2 ), the iNat community is definitely under-observing Canada's total real biodiversity pool with the largest potential observation gap being of what lives in and around salt water.
If I were to put myself in the shoes of somebody who just wants to (1) receive some Nature therapy, (2) improve the community data efforts on iNaturalist, (3) increase their chances of encountering a new (to them) animal, (4) and/or play the iNaturalist game of adding to their backyard species list...this first look at Canadian biodiversity data on iNat tells me that I could check off all those boxes in one afternoon by planning for a walk along the nearest beach or rocky intertidal habitat during the next decent low tide (<0.5 m during daylight).
[1] Biodiversity of Canada project
[2] Marine Biodiversity of Canada project
[3] Marine Biodiversity of Pacific Canada project
[4] Marine Biodiversity of Atantic Canada project
[5] Marine Biodiversity of Arctic Canada project
[6] Marine Sponges of the Pacific Northwest
Comentários
Cool- great overview @jackson_chu. I've shared it with our summer iNat team
Another fascinating journal post @jackson_chu. You're on fire! I have lots of questions... I'm interested to see where you go with this/what else you find.
Out of interest, what's the percent area for each marine project in the umbrella?
@bstarzomski Cool! Hope the team has another big year.
@earley_bird - that's a good and tricky question. Feel free to fire questions, can't promise I have an answer or will have thought about it yet.
In terms of the of the original polygons capturing the exclusive economic zone area, I'll have to look at those original shapefiles and do the calculations. But in general the relative size of each Ocean's footprint is like this:
Arctic >>>> Atlantic >> Pacific.
In terms of the how to capture this on iNaturalist - I don't have a reproducible strategy for this yet. Vast majority of the marine observations are geolocated to the strip of land that is around the high-tide line (a bit below and a bit above...).
451, 373 km2 = Pacific Canada exclusive economic zone (EEZ) area
1,663,940 km2 = Atlantic Canada EEZ
3,625,231 km2 = Arctic Canada EEZ
Based on area of polygons from https://www.marineregions.org/
Thanks @jackson_chu!
So of the total area (5,740,544km2) of Canada's oceans:
Arctic = ~63%
Atlantic = ~29%
Pacific = ~8%.
Of the total (422,883) Canadian marine obs. on iNat:
Arctic = ~0.7%
Atlantic = ~19%
Pacific = ~80%
So the BC (Pacific) marine obs. are doing much of the heavy lifting for marine obs. despite being the smallest percentage of the total area of the Canadian marine environments.
In BC (3,474,325 total) the observations are surprisingly marine "heavy" compared to the rest of the country:
Terrestrial = ~90% of obs... ~68% of total area (944,732km2)
Marine = ~10% of obs... ~32% of total area (451,373km2)
None of those numbers are really leading anywhere, but they're food for thought.
BC terrestrial area from: https://www150.statcan.gc.ca/n1/pub/11-402-x/2010000/chap/geo/tbl/tbl07-eng.htm
Numbers check out.
The eastern Pacific ocean is well known to be a high diversity region because of general oceanographic characteristics. Arctic and Atlantic are expected to be low in diversity. I have yet to get up to the Arctic, but my intertidal walks along the Bay of Fundy shoreline this week sure have been a bit bland and demotivating...I've seen 3 species of seaweeds, 3 bivalves, one snail, and a barnacle.
Makes me wonder if "realized global biodiversity patterns' dictates community science buy-in". As in, globally - areas that are known to be high in biodiversity influences community science engagement as quantified through total observations / observers.
Seems obvious...don't know if the verdict is in.
Adicionar um Comentário