Description
The surface areas of 12 subtidal seagrass Zostera muelleri beds at the islands and adjacent mainland shores of the eastern Bay of Islands (35° 12′ S, 174° 10′ E), New Zealand were estimated from aerial images. It appears that little subtidal seagrass existed until after the early-1950s, so significant beds here may be a relatively recent biome. Possible explanations for recent emergence of subtidal seagrass include that debilitating periods of turbid water and pulses of sedimentation associated with the land clearances of the late 1800s had worked through the marine ecosystem. An overall peak in seagrass-cover in the 1960s to 1980s was followed by declines in several beds in the 1990s to 2000s, with recovery since. The temporal presence of seagrass was well-correlated among the three mainland beds, and moderately well among the south-facing beds on the islands, consistent with mechanisms driving seagrass establishment and persistence operating at reasonably broad scales.
Data Records
The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 243 records.
This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.
Versions
The table below shows only published versions of the resource that are publicly accessible.
How to cite
Researchers should cite this work as follows:
Booth J (2024). Recent (post-1930) changes in the extent of subtidal seagrass (Zostera muelleri) beds of the eastern Bay of Islands, New Zealand. Version 1.4. Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node. Occurrence dataset. https://nzobisipt.niwa.co.nz/resource?r=zostrea_boi_nz&v=1.4
Rights
Researchers should respect the following rights statement:
The publisher and rights holder of this work is Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.
GBIF Registration
This resource has been registered with GBIF, and assigned the following GBIF UUID: a8786b61-49b6-4d45-afc1-4d50bc434e50. Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Ocean Biodiversity Information System.
Keywords
Occurrence; Observation
Contacts
- Metadata Provider ●
- Originator ●
- Point Of Contact
- User
Geographic Coverage
Bay of Islands, New Zealand
| Bounding Coordinates | South West [-35.236, 174.161], North East [-35.212, 174.262] |
|---|
Taxonomic Coverage
Seagrass
| Species | Zostrea muelleri (Seagrass) |
|---|
Temporal Coverage
| Start Date / End Date | 1935-01-01 / 2017-12-31 |
|---|
Sampling Methods
Interpretation from aerial photography
| Study Extent | Bay of Islands, New Zealand |
|---|
Method step description:
- Aerial images useful in defining the extent of the main subtidal seagrass beds over time were scanned/downloaded, with particular focus on early (pre-satellite) ones. The aim was to acquire a time-series, with at least one image every decade through to the present, that could be used to identify any large-scale (on the order of ≥20%) changes in the seagrass footprint. High-resolution imagery spanning multiple beds was particularly useful because such depictions typically included well-established beds that provided reference for smaller and less well-known ones. Images taken at intervals shorter than a decade – even those separated by a year – were also useful because they could potentially indicate how much the surface manifestation of the seagrass beds changed over short timeframes. (Although plant-condition is important in the dynamics of seagrass, this is not readily assessed from aerial imagery. As it turned out, almost all images were from spring and summer, when this seagrass is typically most lush.
Bibliographic Citations
- Booth, J.D., 2019. Recent (post-1930) changes in the extent of subtidal seagrass (Zostera muelleri) beds of the eastern Bay of Islands, New Zealand. New Zealand Journal of Marine and Freshwater Research, 53(1), pp.113-127. https://doi.org/10.1080/00288330.2018.1513409
Additional Metadata
marine, harvested by iOBIS
| Alternative Identifiers | a8786b61-49b6-4d45-afc1-4d50bc434e50 |
|---|---|
| https://nzobisipt.niwa.co.nz/resource?r=zostrea_boi_nz |