Table 1.
Relationship codebook.
| Relationship | Type | Definition |
|---|---|---|
| Ship co-location | One-mode | For each month, a ship-to-ship network was created by determining whether the ships were co-located within 3 km of each other at the same time based on route trajectories (excluding major ports) |
| Ship at location | Two-mode | A ship was considered to be arriving at a port or island if it broadcast an AIS location within a certain distance threshold (five nautical miles). If a ship’s location was determined to be within the threshold for multiple ports, the closest port was considered its destination |
| Ship to company | Two-mode | A ship was tied to a company when a company was listed as the ship’s owner, operator, document compliance company, manager, or technical manager |
| Company to company | One-mode | A subsidiary company was tied to its parent company |
Table 2.
Temporal network level metrics.
| Time | Period | Size | Edges | Average degree | Average clustering coefficient | Degree centralization | Betweenness centralization |
|---|---|---|---|---|---|---|---|
| T0 | November 2014 | 34 | 41 | 2.412 | 0.422 | 0.103 | 0.013 |
| T1 | December 2014 | 24 | 36 | 3.000 | 0.561 | 0.159 | 0.043 |
| T2 | January 2015 | 36 | 107 | 5.944 | 0.578 | 0.133 | 0.035 |
| T3 | February 2015 | 48 | 201 | 8.375 | 0.708 | 0.181 | 0.072 |
| T4 | March 2015 | 75 | 469 | 12.507 | 0.691 | 0.154 | 0.032 |
| T5 | April 2015 | 82 | 781 | 19.049 | 0.711 | 0.206 | 0.048 |
| T6 | May 2015 | 99 | 898 | 18.141 | 0.657 | 0.138 | 0.026 |
| T8 | June 2015 | 122 | 1,451 | 23.787 | 0.698 | 0.168 | 0.042 |
| T9 | July 2015 | 124 | 1,087 | 17.532 | 0.661 | 0.174 | 0.044 |
| T10 | August 2015 | 97 | 768 | 15.835 | 0.687 | 0.143 | 0.051 |
| T11 | September 2015 | 90 | 845 | 18.778 | 0.729 | 0.183 | 0.035 |
| T12 | October 2015 | 70 | 694 | 19.829 | 0.730 | 0.178 | 0.023 |
| T13 | November 2015 | 67 | 464 | 13.851 | 0.614 | 0.163 | 0.036 |
| T14 | December 2015 | 62 | 400 | 12.903 | 0.694 | 0.151 | 0.053 |
| T15 | January 2016 | 68 | 402 | 11.824 | 0.700 | 0.153 | 0.033 |
| T16 | February 2016 | 53 | 318 | 12.000 | 0.677 | 0.206 | 0.023 |
| T17 | March 2016 | 39 | 153 | 7.846 | 0.653 | 0.205 | 0.067 |
Figure 1:
February 2015 network (left) and activity (right). Nodes sized by betweenness cetrality and colored by vessell type (Yellow – TUGs/Pilot Boats, Teal – Cargo, Red – DREDGERs/Specialized Ships, Blue – Offshore Supply, Light Green – CoastGuard, and Other/Unknown – Gray). On right, lines of a Ship’s Track are colored by type of vessel with islands indicated as blue circle and ports as green circles.
Figure 2:
April 2015 network (left) and activity (right). Nodes sized by betweenness cetrality and colored by vessell type (Yellow – TUGs/pilot boats, TEAL – Cargo, Red – DREDGERs/Specialized Ships, Blue – Offshore Supply, Light Green – Coastguard, Tanker – Brown, and Other/Unknown – Gray). On right, lines of a ship’s track are colored by type of vessel with islands indicated as blue circle and ports as green circles.
Figure 3:
November 2015 network (left) and activity (Right). Nodes sized by betweenness cetrality and colored by vessell type (Yellow – TUGs/Pilot Boats, TEAL – Cargo, Red – DREDGERs/Specialized Ships, Blue – Offshore Supply, Light GREEN – Coastguard, Tanker – Brown, Fishing Vessel Purple, and Other/Unknown – Gray). On right, lines of a ship’s track are colored by type of vessel with islands indicated as blue circle and ports as green circles.
Figure 4:
Location to location network, nodes size by authority score and colored with Spratley islands (Orange), Paracel Islands (Purple), and Ports (Green).
Table 3.
Top 10 hubs and authorities.
| Top 10 hubs | Hub score | Top 10 authorities | Authority score |
|---|---|---|---|
| Fiery Cross Reef | 1.000 | Mischief Reef | 1.000 |
| Johnson Reef South | 0.698 | Fiery Cross Reef | 0.682 |
| Mischief Reef | 0.683 | Subi Reef | 0.567 |
| Subi Reef | 0.660 | Johnson Reef South | 0.513 |
| Hughes Reef | 0.406 | Gaven Reef | 0.380 |
| Gaven Reef | 0.366 | Hughes Reef | 0.369 |
| Sanya (Port) | 0.352 | Sanya (Port) | 0.289 |
| Second Thomas Reef | 0.346 | Cuarteron Reef | 0.219 |
| Cuarteron Reef | 0.190 | Second Thomas Reef | 0.164 |
| Basuo (Port) | 0.128 | Basuo (Port) | 0.102 |
Figure 5:
Network of companies with entities explicitly part of the Chinese Government highlighted in orange (left). Network on right shows companies with Chinese Government and isolates removed. Nodes sized by inverse constraint, colored by component with CCCC component – Red, COSCO and China Huaneng Group – Blue.
Table 4.
Top 10 companies with lowest constraint.
| Name | Constraint | Component color |
|---|---|---|
| China Communications Construction Company Ltd (CCCC) | 0.162 | Red |
| Shenzhen Ocean Shipping Co Ltd (COSCO SHENZHEN) | 0.275 | Blue |
| CCCC Tianjin Dredging Co Ltd | 0.309 | Red |
| China Huaneng Group Co Ltd | 0.321 | Blue |
| China COSCO Shipping Corp Ltd | 0.328 | Blue |
| CCCC Shanghai Dredging Co Ltd | 0.331 | Red |
| COSCO Shipping Seafarer Mgmt | 0.355 | Blue |
| Tianjin Cosbulk Ship Mgmt | 0.361 | Blue |
| ICBC Financial Leasing Co Ltd | 0.367 | Blue |
| COSCO Bulk Carrier Co Ltd (COSCO BULK) | 0.368 | Blue |